Some of the most common ocular conditions today:
•EYESTRAIN
•TIRED EYES
•NEAR BLUR
With the boom in the technology market, we now have more people using computers/tablets/smartphones than ever before… and with a broad range of age groups using them! We see 2 year olds and 90 year olds with the same tablet nowadays!
Some of the most common ocular conditions that come from this increased use of technology are:
•Eyestrain
•Tired Eyes/Fatigue
•Near Blur
OCULAR ANATOMY:
•Ciliary Body & Muscles
•Crystalline Lens
•Zonule Fibers
•Iris
To learn about why these conditions come up, we have to learn about how the eye is put together and how it works. Let’s start with the anatomy of the eye.
The ocular components that are responsible for focusing on objects clearly and causing eyestrain, fatigue, near blur are:
The ciliary body
The crystalline lens inside your eye
The zonule fibers that connect the ciliary body to the lens
The iris that show us what color our eyes are
The Ciliary Body:
•Mostly composed of involuntary muscles
•Autonomic Nervous System
•SNS, PNS
A ring of smooth muscle fibers (the muscles inside the ciliary body) that is responsible for changing the shape of the lens in the eye to achieve accommodation.
Suspensory ligaments (the zonule fibers) connect the ciliary muscle to the lens.
The contraction and relaxation of the ciliary muscle is controlled by the autonomic nervous system.
The Crystalline Lens:
•Mostly composted of protein fibers
•Composed of 4 layers
-Sympathetic nerve fiber stimulation causes relaxation of the ciliary muscle. à 2 things occur: 1) lens is focused on distance objects and, 2) minor pupil dilation (aka: pupil mydriasis)
-Parasympathetic stimulation causes ciliary muscle contraction. à 2 things occur: 1) lens is focused on near objects and, 2) minor pupil constriction (aka: pupil miosis)
•Mostly composted of protein fibers
•Composed of 4 layers
The crystalline lens is located just behind the iris.
The lens is made of 4 layers from outside to inside:
•Capsule
•Subcapsule
•Cortex
•Nucleus
As we will discuss later, this lens is very flexible and responsible for changing shape in order to focus on distance and near objects.
Zonule Fibers/Suspensory Fibers
Suspensory Ligaments:
Slender but very strong suspensory ligaments, also known as zonules, attach at one end to the lens capsule and at the other end to the ciliary processes of the ciliary body. These thin ligaments or zonules hold the lens in place.
These zonule fibers, along with the ciliary body, are responsible for changing the shape of the lens.
As the ciliary muscles flex and relax, the zonules decrease and increase tension, respectively. This will change the shape of the lens so it can focus on objects clearly.
The Iris:
Composted of pigment and muscle fibers
The iris is composed of 3 layers, from the front to the back:
-Endothelium
-Stroma
-Epithelium
In the middle of a normal iris is the pupil. It is an opening that, typically, is circular and is comparable to the aperture of a camera. The pupil helps regulate the amount of light passing through to the retina, which is at the back of the eye.
The iris determines the pupil size by contracting different muscles and therefore determine how much light gets into the eye. This becomes especially important in dim light conditions like dark rooms or night time, where the pupil will become larger so more light can come into the eye.
The Iris Reflex:
•Control in bright/dim conditions
•In dim conditions, more light is allowed to enter so that a clear image can be formed on the retina.
•In bright conditions less light is allowed to enter so that the retina is not damaged.
•This adjustment is done by two sets of muscles in the iris:
-It’s circular (sphincter) muscles contract to close up the iris, making the pupil smaller, constricting them.
-It’s radial (dilator) muscles contract to open up the iris, making the pupil larger, dilating them.
Watching television in a dark room gives some people eye aches or headaches. This is because as the brightness of the television screen fluctuates considerably every few seconds. This causes the dilator and sphincter iris muscles controlling the pupil to have to work overtime, constantly adjusting the ever-changing levels of light entering the eye.
Light’s Journey:
•Cornea ->
•Pupil ->
•Lens ->
•Retina
Light enters through the pupil, and is focused by the cornea and the lens onto the retina.
The retina then converts the light into an electrical signal and sends the visual information to the brain. Amazing!
Accommodation
•Near = contracted muscles
•Distance = relaxed muscles
The shape of the lens can be changed by the ciliary muscles so that the image always comes to a sharp focus at the retina.
The ability of the lens to change its shape to focus near and distant objects is called accommodation.
When the ciliary muscle is relaxed the ligaments are taut, and the lens is stretched thin enabling it to focus on distant objects.
When the ciliary muscle is contracted the suspensory ligaments become less taut, and the lens becomes rounder so that it can focus on objects that are nearby
Accommodation
•Distance
•Near Again… in a simpler explanation:
•When the eye’s ciliary muscle is relaxed, the lens focuses on distant objects.
•When the eye’s ciliary muscle is contracted or flexed, the lens focuses on objects that are nearby.
Presbyopia:
•Happens to every single human being!
•Typically at or older than 40 years of age
After age 40 in most people (both males and females), and by age 45 in virtually all, a clear, comfortable focus at near objects becomes more difficult with eyes.
This normal condition is known as PRESBYOPIA and it is primarily due to a hardening and lessening of flexibility of the crystalline lens.
Another factor is a generalized weakening of the ciliary muscle, which we know is responsible to causes the lens to accommodate (change focus).
FUN FACT: Did you know this process of presbyopia (lens hardening and ciliary muscle weakening) actually begins at the AGE OF 6???? It just doesn’t catch up to us until our 40s.
By the time one reaches age 65 or so, the crystalline lens is virtually incapable of changing shape. Unless one is nearsighted by a certain amount, it is not possible to focus objects (such as print on a page) clearly even at an arm’s length distance.
Interestingly, the 1st symptom of presbyopia often is not blurred print or eyestrain while reading…
Rather, one may observe that objects across the room appear momentarily blurry after looking away from a near distance (for example, after reading, writing, or viewing a computer screen for awhile). This is because the crystalline lens have become less flexible than they used to be, resulting in their being less able to accommodate (change focus) from near to far.
The amount of presbyopia inevitably increases with age. Therefore, the additional “plus power” of the lens strength required to maintain a clear, unstrained focus at near will need to be increased every year or so to compensate for the irreversible effect of the presbyopia.
FUN FACT: The wearing of reading glasses for presbyopia does not cause one’s near vision without the glasses to get worse. Presbyopia increases as one ages, regardless of whether or not glasses are worn for near tasks.
Technology & Digital Eyestrain:
•Who?
•Gender: Women > Men
•Age: More commonly in adults <55 years of age
•Lifestyle: On a computer all day
-Digital eyestrain is now the most common computer-related repetitive strain injury among workers, surpassing carpal tunnel syndrome and tendonitis.
In 2012 The Vision Council conducted a survey of 10,000 adults, age 18 and older, about their use of digital media and accompanying symptoms of vision problems. It revealed:
•More than 66% of adults who report regular use of digital media devices experience symptoms of digital eyestrain.
•More than 70% of adults had no previous knowledge about digital eyestrain as a real health issue.
•Only 23% of adults are aware that special digital-use eyewear exists that can help reduce symptoms.
Gender:
Women are more likely than men to experience problems associated with digital eyestrain.
•About 33% of women report eyestrain and neck and shoulder pain.
•At least 20% of women has suffered dry eyes (24%), blurred vision (22%) and headaches (23%).
Age:
Digital eyestrain symptoms are common in adults under 55.
•Adults ages 45 and older are 14-23% less likely to experience headaches compared to their younger counterparts.
Lifestyle:
Individuals who primarily use digital media for work are more likely to experience symptoms of digital eyestrain — whether a higher incidence of:
•Eyestrain (39%)
•Neck and shoulder pain (42%)
•Dry eyes (25%)
•Blurred vision (23%)
Computer Vision Syndrome:
•Constant ciliary muscle contraction for several continuous hours…
SYMPTOMS:
Computer Vision Syndrome describes a group of eye and vision-related problems that result from prolonged computer use. Many individuals experience eye discomfort and vision problems when viewing a computer screen for extended periods. The level of discomfort appears to increase with the amount of computer use.
As we discussed earlier, the ciliary muscle is contracted when focusing on a near object (like a computer screen or tablet). Well, if you do this for several continuous hours at a time, it is analogous to you holding a 10lb dumbbell with your arm non-stop for the same amount of time. Your eyes will start fatiguing and become strained. It is then when symptoms may arise.
The most common symptoms associated with Computer Vision Syndrome (CVS) are:
•Eyestrain
•Headaches
•Blurred vision
•Dry eyes
•Neck and Shoulder Pain
Many symptoms are only temporary and will decline after stopping computer work. However, some individuals may experience continued reduced visual abilities, such as blurred distance vision, even after stopping work at a computer. These symptoms will continue to recur and perhaps worsen.
Computer Vision Syndrome:
•What causes CVS?
•Uncorrected Vision Problems
•On a computer 2 or more hours/day
These symptoms may be caused by:
•Poor lighting
•Glare from screen
•Improper viewing distances
•Poor posture
•Uncorrected vision problems
In addition, the presence of even minor vision problems can often significantly affect comfort and performance at a computer. Uncorrected vision problems like farsightedness and astigmatism, inadequate eye focusing or eye coordination abilities, and aging changes of the eyes, such as presbyopia, can all contribute to the development of visual symptoms when using a computer.
Viewing a computer screen often makes the eyes work harder. As a result, the unique characteristics and high visual demands of computer viewing make many individuals susceptible to the development of vision-related symptoms.
•Letters on the computer screen are not as precise or sharply defined as words on a paper
•Level of contrast of the letters to the background is reduced
•Presence of glare and reflections on the screen make viewing difficult
•Viewing distances and angles used for computer work are different from those commonly used for other reading or writing tasks
As a result, the eye focusing and eye movement requirements for computer viewing can place additional demands on the visual system.
Even people who have an eyeglass or contact lens prescription may find it's not suitable for the specific viewing distances of their computer screen. Some people tilt their heads at odd angles because their glasses aren't designed for looking at a computer. Or they bend toward the screen in order to see it clearly. Their postures can result in muscle spasms or pain in the neck, shoulder or back.
In most cases, symptoms of CVS occur because the visual demands of the task exceed the visual abilities of the individual to comfortably perform them. At greatest risk for developing CVS are those persons who spend 2 or more continuous hours at a computer every day.
Computer Vision Syndrome:
•How do I reduce my vision problems related to CVS?
•See Your Optometrist
•Computer Glasses
•Anti-Reflective Lenses
•Vision Therapy
Prevention or reduction of the vision problems associated with Computer Vision Syndrome involves taking steps to control lighting and glare on the computer screen, establishing proper working distances and posture for computer viewing, and assuring that even minor vision problems are properly corrected.
Solutions to computer-related vision problems are varied. However, CVS can usually be alleviated by obtaining regular eye care and making changes in how you view the computer screen.
COMPUTER GLASSES – In some cases, individuals who do not require the use of eyeglasses for other daily activities may benefit from glasses prescribed specifically for computer use. In addition, persons already wearing glasses may find their current prescription does not provide optimal vision for viewing a computer.
ANTI-REFLECTIVE LENSES – Eyeglasses or contact lenses prescribed for general use may not be adequate for computer work. Lenses prescribed to meet the unique visual demands of computer viewing may be needed. Special lens designs, lens powers or lens tints or coatings may help to maximize visual abilities and comfort.
VISION THERAPY – Some computer users experience problems with eye focusing or eye coordination that can't be adequately corrected with eyeglasses or contact lenses. A program of vision therapy may be needed to treat these specific problems. Vision therapy, also called visual training, is a structured program of visual activities prescribed to improve visual abilities. It trains the eyes and brain to work together more effectively. These eye exercises help remediate deficiencies in eye movement, eye focusing and eye teaming and reinforce the eye-brain connection. Treatment may include office-based as well as home training procedures.
Technology & Digital Eyestrain:
•Insomnia
•Blue Light from digital screens
•Fluorescent Bulbs
•Especially in Children
The American Medical Association (AMA) issued a policy recognizing "that exposure to excessive light at night, including extended use of various electronic media, can disrupt sleep or exacerbate sleep disorders, especially in children and adolescents.“
Any light at night can be disruptive, researchers say, but in recent years studies have zeroed in on the particularly potent "blue light" emitted abundantly from the energy-efficient screens of smartphones and computers as well as many energy-saving fluorescent bulbs.
Because blue light is especially prominent in daylight, our bodies associate it with daytime, which may be why exposure to blue light can make us more alert and improve our response times. It also has been shown to suppress melatonin, a hormone that helps regulate sleep and is not produced during the day.
In May 2011, Swiss researchers at the University of Basel reported that subjects who spent time at night in front of an LED computer screen, as opposed to a screen emitting a variety of colors but little blue light, experienced "a significant suppression of the evening rise in endogenous melatonin and … sleepiness.“
"Blue light preferentially alerts the brain, suppresses the melatonin and shifts your body clock all at the same time," said Harvard Medical S chool sleep researcher Steven Lockley. "Your brain is more alert now and thinks it's daytime because we have evolved to only see bright light during the day."
Compounding the problem, Lockley and others said, is that unlike TV (which also emits blue light), these newer electronic screens are positioned close to our faces, increasing the intensity and effects of the blue light on our brains. "The closer you have a light source to the face, the more intense it is," said Lockley, co-author of "Sleep: A Very Short Introduction." "And the further you go away, it falls off quite quickly. So having things close to the face is much worse than having a TV that's 10 feet away."
Increasingly, however, consumers are using devices that emit blue light well into the night. A recent poll by Rosetta marketing consultants indicated that today almost 1 in 3 Americans who use the internet own a tablet and that 68% of them report taking the device to bed.
Prevention & Healthy Habits:
•See Your Optometrist
•Ergonomics
•Proper Posture
•Breaks
•Air Quality
Ergonomics - proper body positioning for computer use:
This includes lighting conditions, chair comfort, location of reference materials, position of the monitor, and the use of rest breaks.
Location of computer screen - Most people find it more comfortable to view a computer when the eyes are looking downward. Optimally, the computer screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen and 20 to 28 inches from the eyes.
Reference materials - These materials should be located above the keyboard and below the monitor. If this is not possible, a document holder can be used beside the monitor. The goal is to position the documents so you do not need to move your head to look from the document to the screen.
Lighting - Position the computer screen to avoid glare, particularly from overhead lighting or windows. Use blinds or drapes on windows and replace the light bulbs in desk lamps with bulbs of lower wattage.
Anti-glare screens - If there is no way to minimize glare from light sources, consider using a screen glare filter. These filters decrease the amount of light reflected from the screen.
Seating position - Chairs should be comfortably padded and conform to the body. Chair height should be adjusted so your feet rest flat on the floor. If your chair has arms, they should be adjusted to provide arm support while you are typing. Your wrists shouldn't rest on the keyboard when typing.
Rest breaks - To prevent eyestrain, try to rest your eyes when using the computer for long periods. Rest your eyes for 15 minutes after two hours of continuous computer use. Also, for every 20 minutes of computer viewing, look into the distance for 20 seconds to allow your eyes a chance to refocus.
Blinking - To minimize your chances of developing dry eye when using a computer, make an effort to blink frequently. Blinking keeps the front surface of your eye moist.
Improve the air quality in your work space – Some changes that may help prevent dry eyes include using a humidifier, lowering the thermostat and avoiding smoke.
Get appropriate eyewear - If you wear glasses or contacts, make sure the correction is right for computer work. Most lenses are fitted for reading print and may not be optimal for computer work. Glasses or contact lenses designed specifically for computer work may be a worthwhile investment.
Regular eye examinations and proper viewing habits can help to prevent or reduce the development of the symptoms associated with Computer Vision Syndrome.
•EYESTRAIN
•TIRED EYES
•NEAR BLUR
With the boom in the technology market, we now have more people using computers/tablets/smartphones than ever before… and with a broad range of age groups using them! We see 2 year olds and 90 year olds with the same tablet nowadays!
Some of the most common ocular conditions that come from this increased use of technology are:
•Eyestrain
•Tired Eyes/Fatigue
•Near Blur
OCULAR ANATOMY:
•Ciliary Body & Muscles
•Crystalline Lens
•Zonule Fibers
•Iris
To learn about why these conditions come up, we have to learn about how the eye is put together and how it works. Let’s start with the anatomy of the eye.
The ocular components that are responsible for focusing on objects clearly and causing eyestrain, fatigue, near blur are:
The ciliary body
The crystalline lens inside your eye
The zonule fibers that connect the ciliary body to the lens
The iris that show us what color our eyes are
The Ciliary Body:
•Mostly composed of involuntary muscles
•Autonomic Nervous System
•SNS, PNS
A ring of smooth muscle fibers (the muscles inside the ciliary body) that is responsible for changing the shape of the lens in the eye to achieve accommodation.
Suspensory ligaments (the zonule fibers) connect the ciliary muscle to the lens.
The contraction and relaxation of the ciliary muscle is controlled by the autonomic nervous system.
The Crystalline Lens:
•Mostly composted of protein fibers
•Composed of 4 layers
-Sympathetic nerve fiber stimulation causes relaxation of the ciliary muscle. à 2 things occur: 1) lens is focused on distance objects and, 2) minor pupil dilation (aka: pupil mydriasis)
-Parasympathetic stimulation causes ciliary muscle contraction. à 2 things occur: 1) lens is focused on near objects and, 2) minor pupil constriction (aka: pupil miosis)
•Mostly composted of protein fibers
•Composed of 4 layers
The crystalline lens is located just behind the iris.
The lens is made of 4 layers from outside to inside:
•Capsule
•Subcapsule
•Cortex
•Nucleus
As we will discuss later, this lens is very flexible and responsible for changing shape in order to focus on distance and near objects.
Zonule Fibers/Suspensory Fibers
Suspensory Ligaments:
Slender but very strong suspensory ligaments, also known as zonules, attach at one end to the lens capsule and at the other end to the ciliary processes of the ciliary body. These thin ligaments or zonules hold the lens in place.
These zonule fibers, along with the ciliary body, are responsible for changing the shape of the lens.
As the ciliary muscles flex and relax, the zonules decrease and increase tension, respectively. This will change the shape of the lens so it can focus on objects clearly.
The Iris:
Composted of pigment and muscle fibers
The iris is composed of 3 layers, from the front to the back:
-Endothelium
-Stroma
-Epithelium
In the middle of a normal iris is the pupil. It is an opening that, typically, is circular and is comparable to the aperture of a camera. The pupil helps regulate the amount of light passing through to the retina, which is at the back of the eye.
The iris determines the pupil size by contracting different muscles and therefore determine how much light gets into the eye. This becomes especially important in dim light conditions like dark rooms or night time, where the pupil will become larger so more light can come into the eye.
The Iris Reflex:
•Control in bright/dim conditions
•In dim conditions, more light is allowed to enter so that a clear image can be formed on the retina.
•In bright conditions less light is allowed to enter so that the retina is not damaged.
•This adjustment is done by two sets of muscles in the iris:
-It’s circular (sphincter) muscles contract to close up the iris, making the pupil smaller, constricting them.
-It’s radial (dilator) muscles contract to open up the iris, making the pupil larger, dilating them.
Watching television in a dark room gives some people eye aches or headaches. This is because as the brightness of the television screen fluctuates considerably every few seconds. This causes the dilator and sphincter iris muscles controlling the pupil to have to work overtime, constantly adjusting the ever-changing levels of light entering the eye.
Light’s Journey:
•Cornea ->
•Pupil ->
•Lens ->
•Retina
Light enters through the pupil, and is focused by the cornea and the lens onto the retina.
The retina then converts the light into an electrical signal and sends the visual information to the brain. Amazing!
Accommodation
•Near = contracted muscles
•Distance = relaxed muscles
The shape of the lens can be changed by the ciliary muscles so that the image always comes to a sharp focus at the retina.
The ability of the lens to change its shape to focus near and distant objects is called accommodation.
When the ciliary muscle is relaxed the ligaments are taut, and the lens is stretched thin enabling it to focus on distant objects.
When the ciliary muscle is contracted the suspensory ligaments become less taut, and the lens becomes rounder so that it can focus on objects that are nearby
Accommodation
•Distance
•Near Again… in a simpler explanation:
•When the eye’s ciliary muscle is relaxed, the lens focuses on distant objects.
•When the eye’s ciliary muscle is contracted or flexed, the lens focuses on objects that are nearby.
Presbyopia:
•Happens to every single human being!
•Typically at or older than 40 years of age
After age 40 in most people (both males and females), and by age 45 in virtually all, a clear, comfortable focus at near objects becomes more difficult with eyes.
This normal condition is known as PRESBYOPIA and it is primarily due to a hardening and lessening of flexibility of the crystalline lens.
Another factor is a generalized weakening of the ciliary muscle, which we know is responsible to causes the lens to accommodate (change focus).
FUN FACT: Did you know this process of presbyopia (lens hardening and ciliary muscle weakening) actually begins at the AGE OF 6???? It just doesn’t catch up to us until our 40s.
By the time one reaches age 65 or so, the crystalline lens is virtually incapable of changing shape. Unless one is nearsighted by a certain amount, it is not possible to focus objects (such as print on a page) clearly even at an arm’s length distance.
Interestingly, the 1st symptom of presbyopia often is not blurred print or eyestrain while reading…
Rather, one may observe that objects across the room appear momentarily blurry after looking away from a near distance (for example, after reading, writing, or viewing a computer screen for awhile). This is because the crystalline lens have become less flexible than they used to be, resulting in their being less able to accommodate (change focus) from near to far.
The amount of presbyopia inevitably increases with age. Therefore, the additional “plus power” of the lens strength required to maintain a clear, unstrained focus at near will need to be increased every year or so to compensate for the irreversible effect of the presbyopia.
FUN FACT: The wearing of reading glasses for presbyopia does not cause one’s near vision without the glasses to get worse. Presbyopia increases as one ages, regardless of whether or not glasses are worn for near tasks.
Technology & Digital Eyestrain:
•Who?
•Gender: Women > Men
•Age: More commonly in adults <55 years of age
•Lifestyle: On a computer all day
-Digital eyestrain is now the most common computer-related repetitive strain injury among workers, surpassing carpal tunnel syndrome and tendonitis.
In 2012 The Vision Council conducted a survey of 10,000 adults, age 18 and older, about their use of digital media and accompanying symptoms of vision problems. It revealed:
•More than 66% of adults who report regular use of digital media devices experience symptoms of digital eyestrain.
•More than 70% of adults had no previous knowledge about digital eyestrain as a real health issue.
•Only 23% of adults are aware that special digital-use eyewear exists that can help reduce symptoms.
Gender:
Women are more likely than men to experience problems associated with digital eyestrain.
•About 33% of women report eyestrain and neck and shoulder pain.
•At least 20% of women has suffered dry eyes (24%), blurred vision (22%) and headaches (23%).
Age:
Digital eyestrain symptoms are common in adults under 55.
•Adults ages 45 and older are 14-23% less likely to experience headaches compared to their younger counterparts.
Lifestyle:
Individuals who primarily use digital media for work are more likely to experience symptoms of digital eyestrain — whether a higher incidence of:
•Eyestrain (39%)
•Neck and shoulder pain (42%)
•Dry eyes (25%)
•Blurred vision (23%)
Computer Vision Syndrome:
•Constant ciliary muscle contraction for several continuous hours…
SYMPTOMS:
Computer Vision Syndrome describes a group of eye and vision-related problems that result from prolonged computer use. Many individuals experience eye discomfort and vision problems when viewing a computer screen for extended periods. The level of discomfort appears to increase with the amount of computer use.
As we discussed earlier, the ciliary muscle is contracted when focusing on a near object (like a computer screen or tablet). Well, if you do this for several continuous hours at a time, it is analogous to you holding a 10lb dumbbell with your arm non-stop for the same amount of time. Your eyes will start fatiguing and become strained. It is then when symptoms may arise.
The most common symptoms associated with Computer Vision Syndrome (CVS) are:
•Eyestrain
•Headaches
•Blurred vision
•Dry eyes
•Neck and Shoulder Pain
Many symptoms are only temporary and will decline after stopping computer work. However, some individuals may experience continued reduced visual abilities, such as blurred distance vision, even after stopping work at a computer. These symptoms will continue to recur and perhaps worsen.
Computer Vision Syndrome:
•What causes CVS?
•Uncorrected Vision Problems
•On a computer 2 or more hours/day
These symptoms may be caused by:
•Poor lighting
•Glare from screen
•Improper viewing distances
•Poor posture
•Uncorrected vision problems
In addition, the presence of even minor vision problems can often significantly affect comfort and performance at a computer. Uncorrected vision problems like farsightedness and astigmatism, inadequate eye focusing or eye coordination abilities, and aging changes of the eyes, such as presbyopia, can all contribute to the development of visual symptoms when using a computer.
Viewing a computer screen often makes the eyes work harder. As a result, the unique characteristics and high visual demands of computer viewing make many individuals susceptible to the development of vision-related symptoms.
•Letters on the computer screen are not as precise or sharply defined as words on a paper
•Level of contrast of the letters to the background is reduced
•Presence of glare and reflections on the screen make viewing difficult
•Viewing distances and angles used for computer work are different from those commonly used for other reading or writing tasks
As a result, the eye focusing and eye movement requirements for computer viewing can place additional demands on the visual system.
Even people who have an eyeglass or contact lens prescription may find it's not suitable for the specific viewing distances of their computer screen. Some people tilt their heads at odd angles because their glasses aren't designed for looking at a computer. Or they bend toward the screen in order to see it clearly. Their postures can result in muscle spasms or pain in the neck, shoulder or back.
In most cases, symptoms of CVS occur because the visual demands of the task exceed the visual abilities of the individual to comfortably perform them. At greatest risk for developing CVS are those persons who spend 2 or more continuous hours at a computer every day.
Computer Vision Syndrome:
•How do I reduce my vision problems related to CVS?
•See Your Optometrist
•Computer Glasses
•Anti-Reflective Lenses
•Vision Therapy
Prevention or reduction of the vision problems associated with Computer Vision Syndrome involves taking steps to control lighting and glare on the computer screen, establishing proper working distances and posture for computer viewing, and assuring that even minor vision problems are properly corrected.
Solutions to computer-related vision problems are varied. However, CVS can usually be alleviated by obtaining regular eye care and making changes in how you view the computer screen.
COMPUTER GLASSES – In some cases, individuals who do not require the use of eyeglasses for other daily activities may benefit from glasses prescribed specifically for computer use. In addition, persons already wearing glasses may find their current prescription does not provide optimal vision for viewing a computer.
ANTI-REFLECTIVE LENSES – Eyeglasses or contact lenses prescribed for general use may not be adequate for computer work. Lenses prescribed to meet the unique visual demands of computer viewing may be needed. Special lens designs, lens powers or lens tints or coatings may help to maximize visual abilities and comfort.
VISION THERAPY – Some computer users experience problems with eye focusing or eye coordination that can't be adequately corrected with eyeglasses or contact lenses. A program of vision therapy may be needed to treat these specific problems. Vision therapy, also called visual training, is a structured program of visual activities prescribed to improve visual abilities. It trains the eyes and brain to work together more effectively. These eye exercises help remediate deficiencies in eye movement, eye focusing and eye teaming and reinforce the eye-brain connection. Treatment may include office-based as well as home training procedures.
Technology & Digital Eyestrain:
•Insomnia
•Blue Light from digital screens
•Fluorescent Bulbs
•Especially in Children
The American Medical Association (AMA) issued a policy recognizing "that exposure to excessive light at night, including extended use of various electronic media, can disrupt sleep or exacerbate sleep disorders, especially in children and adolescents.“
Any light at night can be disruptive, researchers say, but in recent years studies have zeroed in on the particularly potent "blue light" emitted abundantly from the energy-efficient screens of smartphones and computers as well as many energy-saving fluorescent bulbs.
Because blue light is especially prominent in daylight, our bodies associate it with daytime, which may be why exposure to blue light can make us more alert and improve our response times. It also has been shown to suppress melatonin, a hormone that helps regulate sleep and is not produced during the day.
In May 2011, Swiss researchers at the University of Basel reported that subjects who spent time at night in front of an LED computer screen, as opposed to a screen emitting a variety of colors but little blue light, experienced "a significant suppression of the evening rise in endogenous melatonin and … sleepiness.“
"Blue light preferentially alerts the brain, suppresses the melatonin and shifts your body clock all at the same time," said Harvard Medical S chool sleep researcher Steven Lockley. "Your brain is more alert now and thinks it's daytime because we have evolved to only see bright light during the day."
Compounding the problem, Lockley and others said, is that unlike TV (which also emits blue light), these newer electronic screens are positioned close to our faces, increasing the intensity and effects of the blue light on our brains. "The closer you have a light source to the face, the more intense it is," said Lockley, co-author of "Sleep: A Very Short Introduction." "And the further you go away, it falls off quite quickly. So having things close to the face is much worse than having a TV that's 10 feet away."
Increasingly, however, consumers are using devices that emit blue light well into the night. A recent poll by Rosetta marketing consultants indicated that today almost 1 in 3 Americans who use the internet own a tablet and that 68% of them report taking the device to bed.
Prevention & Healthy Habits:
•See Your Optometrist
•Ergonomics
•Proper Posture
•Breaks
•Air Quality
Ergonomics - proper body positioning for computer use:
This includes lighting conditions, chair comfort, location of reference materials, position of the monitor, and the use of rest breaks.
Location of computer screen - Most people find it more comfortable to view a computer when the eyes are looking downward. Optimally, the computer screen should be 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen and 20 to 28 inches from the eyes.
Reference materials - These materials should be located above the keyboard and below the monitor. If this is not possible, a document holder can be used beside the monitor. The goal is to position the documents so you do not need to move your head to look from the document to the screen.
Lighting - Position the computer screen to avoid glare, particularly from overhead lighting or windows. Use blinds or drapes on windows and replace the light bulbs in desk lamps with bulbs of lower wattage.
Anti-glare screens - If there is no way to minimize glare from light sources, consider using a screen glare filter. These filters decrease the amount of light reflected from the screen.
Seating position - Chairs should be comfortably padded and conform to the body. Chair height should be adjusted so your feet rest flat on the floor. If your chair has arms, they should be adjusted to provide arm support while you are typing. Your wrists shouldn't rest on the keyboard when typing.
Rest breaks - To prevent eyestrain, try to rest your eyes when using the computer for long periods. Rest your eyes for 15 minutes after two hours of continuous computer use. Also, for every 20 minutes of computer viewing, look into the distance for 20 seconds to allow your eyes a chance to refocus.
Blinking - To minimize your chances of developing dry eye when using a computer, make an effort to blink frequently. Blinking keeps the front surface of your eye moist.
Improve the air quality in your work space – Some changes that may help prevent dry eyes include using a humidifier, lowering the thermostat and avoiding smoke.
Get appropriate eyewear - If you wear glasses or contacts, make sure the correction is right for computer work. Most lenses are fitted for reading print and may not be optimal for computer work. Glasses or contact lenses designed specifically for computer work may be a worthwhile investment.
Regular eye examinations and proper viewing habits can help to prevent or reduce the development of the symptoms associated with Computer Vision Syndrome.
