California Optometrists Weigh in on ‘The Dress Phenomenon’

0227_crazydressThere’s a lot more to vision than just the eye. Have you ever seen one of those prints where you stare at it long enough until you see the underlying subliminal image? That’s similar to how you see the dress.

The answer: Yes. It’s blue and black (sorry team white/gold).

That doesn’t mean you have anything wrong with your eyes. “There is no specific pattern to the variation in this observation,” says David Ardaya, OD. “Although there may be genetic propensities in color vision deficiencies between men and women, this is primarily a matter of color constancy.”

“Color constancy is where color tends to look the same under widely different viewing conditions. In the case of this dress, our visual cortex interprets the color based on the type of light we perceive to have fallen on it and surrounding it,” says Jason Tu, OD. “We can’t really see the surrounding background so we don’t know what type of light is on this dress – so if our brain were to assume that the background light is natural daylight, it would perceive a certain set of colors as opposed to if we assume the background light to be artificial light.”

Long story short – team blue and black wins. But fear not, team white and gold – for you can see a new perspective on the colors this world has to offer.

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How much time should your child spend on the computer?

138284-425x282-child-on-computerIn our society today, children increasingly use computers, smart phones and tablets on a daily basis. Children as well as adults may experience symptoms related to computer use called computer vision syndrome. Symptoms after extensive viewing of technology can lead to eye discomfort, fatigue, blurred vision and headaches, dry eye and eyestrain. These symptoms may be exacerbated by poor lighting, glare, an improper work station arrangement, uncorrected refractive error (vision problems), or a combination of these factors.

In addition, children may be more susceptible than adults to computer vision syndrome.

Why?

1. Children use an adult computer.
Since a child is smaller than an adult, the computer workstation may not fit them well. Children may have difficulty reaching the keyboard or placing their feet on the floor, causing arm, neck or back discomfort. For example, a child using a computer on a typical office desk often must look up further than an adult. The optimal viewing angle is slightly down at 15 to 20 degrees. If a different viewing angle is used, problems with binocular vision (both eyes working together) can occur.

2. Children are not as self-aware as adults.
A child may use a computer or keep playing video games without taking breaks for many hours. Prolonged activity without breaks can cause accommodative problems. The eyes focus at a particular target, which may cause accommodation spasm. In some cases, the eyes may be unable to smoothly and easily focus on a particular object, even long after the original work is completed. Also, eye irritation may occur due to reduced blinking. When concentrating and viewing a screen, blinking is reduced.

3. Children may ignore problems.
For example, a child may ignore significant glare or poor lighting when viewing a computer screen, which may lead to excessive eyestrain. Intensified light can contribute to excessive glare and problems associated with eye adjustments to different levels of light. Also, children often accept blurred vision caused by nearsightedness (myopia), farsightedness (hyperopia), or astigmatism because they think everyone sees the way they do. Uncorrected refractive error can cause eye strain.

Important tips for children using a computer:

1. A comprehensive eye examination.
Eye examinations are important for all children and adults, starting at 6 months of age. An eye examination will ensure that the child can see clearly and comfortably at all distances and detect conditions that may contribute to eyestrain. If needed, glasses, contact lenses or vision therapy (eye exercises) can provide clear and comfortable vision for computer use.

2. Check the height and arrangement of the computer.
A 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 held 20 to 28 inches away from the eyes. The child’s size should determine where the monitor and keyboard are placed. If the computer monitor is too high in the child’s field of view, an adjustable chair may be used that can be adjusted for the child’s comfort. A footstool may be helpful in supporting the child’s feet.

3. Check for glare on the computer screen.
Windows or other light sources should not be directly visible when sitting in front of the monitor. If needed, adjust the desk or computer to prevent glare on the screen. A lower-wattage light can be substituted for a bright overhead light or a dimmer switch may be installed to give flexible control of room lighting.

4. Take a break.
A 20 second break every 20 minutes will reduce the development of eye focusing problems and eye irritation.

5. Keep blinking.
Remind your child the importance of blinking. In order to minimize the chances of developing dry eye when using a computer or digital device, make an effort to blink frequently. Blinking keeps the front surface of the eye moist. Non-preserved lubricant artificial tears may be helpful for children as well as adults.

~ Melissa Barnett, OD, FAAO
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

Is your smartphone damaging your eye?

sleep-texting1_0For many of us, we spend our days on electronic devices, unknowingly exposing our eyes to light that can cause potential damage years from now. Our smartphones, tablets, and electronic devices emit light of all colors, but researchers are finding that there is a connection between blue light exposure and ocular damage.

For over a decade, the eyecare industry has been working hard to determine the connection. Laboratory studies are finding that after exposure to hours of blue light, the light sensing cells of the retina and its underlying layer begin to show damage, similar to that found in an eye disease called macular degeneration, a leading cause of blindness in the United States.

With these findings, what does this mean for all of us who are on electronic devices all day long? Are we exposing our eyes to harmful light that can cause us to lose our vision? It’s possible and very probable. Until a clinical study on patients shows a definitive correlation between blue light and vision loss, the general public may not be made aware of this potential. That doesn’t mean that you should ignore this finding.

If you or your children are using electronic devices, then you are exposing your eyes to blue light. And this type of chronic and cumulative exposure over decades will almost certainly cause ocular damage in the future. In light of these findings, the eyecare industry has recently made available lenses that block out blue light without distorting color. In the past, blue-blocking lenses tended to have a yellow tint. Manufacturers have now created a clear blue-blocking filter combined with anti-glare coating and ultraviolet protection.

Anybody who purchases glasses these days should already know to add an anti-glare coating with ultraviolet protection on the lenses. The anti-glare coating will improve vision and reduce glare from light sources, while the ultraviolet coating will protect eyes from harmful sunlight. Now, patients should choose an anti-glare coating that comes with ultraviolet protection and blue-blocking filter.

Not all blue light is harmful though. Some blue light helps with regulating your sleep/wake cycle and can affect memory, alertness and mood. Therefore, blue-blocking filters selectively filters out harmful blue light while allowing transmittance of beneficial blue light.

I don’t think any of us will be putting away our tablets to start reading from paper again. And until we know more about blue light, studies are showing it’s not all good. So be sure to protect your eyes and the eyes of children by asking your optometrist for a blue-blocking filter. It’s always better to be safe than sorry.

~ Cindy P. Wang, OD, FAAO
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org