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

The story of a color blind child

Color blind

Photo courtesy of Templatemonster.com

It’s that time of year again. Every fall, our local doctors of optometry, along with school nurses and a plethora of volunteers, corral students through our Lions Club’s Sight Savers trailer performing vision screening. And, every fall I have concerned parents rushing in their children to confirm if there is an eye problem. This year was no different.

Last week I entered my exam room to see a first grader who, it was determined, was color blind. Of course, his father did not believe the testing was correct and proceeded to confirm that his son new ALL of his colors and that there was NO WAY he could be color blind. I pulled out my trusty color vision test; administered the test to the son; and showed that indeed he was color deficient. On one page of the test with the number “35”, a color deficient person would only be able to see one digit. The boy proudly and confidently proclaimed that the number on the page was “5”. Even with prodding and cajoling from the father, his son could only see the number “5”.

A little physiology lesson:

In the retina, there are two types of nerves – cones that see color, and rods that see light. The cones are further differentiated in to three types – one that is stimulated by red light, one by green light and one by blue light. In order to have “normal” color vision, all three cones need to be present. If one of the cones is missing, or more commonly not as sensitive, then the person would have confusion of certain colors. This student has a deficient green cone. I explained this condition to the father and the student and how it would affect him.

For instance:

If we have green paint and mix it with red paint, we make brown paint. (Green + Red = Brown)

If you cannot see the green, then red and brown look the same. (Green + Red = Brown)

If we mix green with blue, we make aqua. So, blue and aqua look the same. (Green + Blue = Aqua)

This confusion of colors is what is known as “color blindness” or more correctly “color deficiency”. I explained that it is important to let the teachers know so they do not grade down for improper answers, and discussed job restriction for color deficient people. The two most common job restrictions are law enforcement and commercial aviation. If a color deficient police officer was told a suspect has a brown coat on and stops someone with a red coat on, that just doesn’t work. I do have several patients who are pilots and are color deficient. They are able to get licensed to fly, but not to fly at night due to the need to differentiate the colored lights on airstrips – no commercial or airliner work.

Facts about color deficiencies:

  • The gene for color deficiency is carried on the X chromosome
  • Somewhere between 8 to 10 percent of the male population in the US is color deficient
  • Less than one half percent of the female population in the US is color deficient
  • Men cannot pass color deficiencies on to their sons; it passes through mothers who are carriers for the gene
  • The incidence of color deficiency is highest in Caucasians; then Asians, then Hispanics, and lowest in African Americans
  • Red-Green defects account for over 95 percent of color deficiencies
  • Blue-yellow color blindnessis a dominant, not sex linked trait, which means both men and women are equally affected.
  • John Dalton wrote the first known scientific paper (1794) regarding color blindness. He was color blind himself.
  • Color deficient people hate to be asked “What color is this?”

~ Steven Sage Hider, OD
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

The famous glasses of Christmas movies, past and present….

Holiday GlassesAll of us have our favorite holiday movies- mine happens to be Elf with Will Ferrell.  And the elves in Santa’s workshop just so happen to wear small triangular reading glasses down on their noses.  Surprising, I did not even notice their glasses until I started to think about it! Glasses on characters in our favorite movies are often the defining characteristic of the character.  If you think about “Ralphie” in A Christmas Story you probably can picture him with brown thick glasses and at the same time recall his mom cautioning him: “You’ll shoot your eye out!.” Or how about Ebenezer Scrooge in “A Christmas Carol” with small reading glasses down on his nose, holding a candle in the dark?

Some other famous Christmas movie characters that wear glasses are Clark Griswold in “Christmas Vacation”, Marcie in “Charlie Brown Christmas”, Arthur in “Arthur’s Christmas” The Conductor in “Polar Express” and of course Santa/Kris Kringle in “A Miracle on 34th Street- just to name a few.

So while you sit back and enjoy your favorite holiday movies this year, notice that sometimes, what adds to our favorite movie character’s charm and distinguishing personality, actually just happens to be their glasses!

~ Lisa M. Weiss, O.D.
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

Vitamin D and the eye

Photo courtesy of www.acneeinstein.com

Photo courtesy of http://www.acneeinstein.com

Many of my patients take an assortment of supplements such as Calcium, Omega-3, Multi-Vitamins with Minerals, and Vitamin D on a daily basis. Are you one of those individuals taking vitamins regularly? And if so, are you taking Vitamin D?

It is a known fact that those that reside high up in the northern hemisphere require taking supplemental Vitamin D because they are not exposed to enough sunlight. You see, just being under the sun for about 15 minutes a day will help your skin convert sunlight into usable Vitamin D for your body to use. You can also get Vitamin D through a diet of fish (herring, mackerel, sardines, tuna) and fortified dairy products.

Nowadays, people are unfortunately becoming more deficient in Vitamin D levels for two reasons: diligent use of sunscreen, which on one hand aids in the prevention of skin cancer, but on the other hand it blocks the skin from producing enough Vitamin D for your body; and a diet lacking in foods rich in Vitamin D.

Vitamin D was originally believed to strengthen our bones. Through the Fall Risk studies, Vitamin D has proven that it goes beyond prevention of osteoporosis. It is involved in the prevention or reduction of symptoms in Alzheimer disease, asthma, breast cancer, colorectal cancer, dental caries, depression, diabetes and Diabetic Retinopathy, eczema, hypertension, inflammatory bowel disease, influenza, Lupus, Multiple Sclerosis and Optic Neuritis, pneumonia/respiratory infections, and tuberculosis.

With the eye in particular, research has revealed that individuals with diabetes had little to no presentation of diabetic retinopathy while taking supplemental Vitamin D. Furthermore, clinical research has shown that individuals recently diagnosed with Multiple Sclerosis and subsequently placed on high dose Vitamin D had both their neurologic signs and symptoms improve. Continued studies are proving that sufficient levels of Vitamin D may ward off episodes of inflammation of the optic nerve in the eye (Optic Neuritis).

From all the known benefits of taking Vitamin D, wouldn’t it be a good idea to check the status of Vitamin D level in your blood? Taking supplemental vitamins can be a controversial subject. If you do decide to jump on the band wagon, it is always a good idea to talk to your primary care physician before you start taking Vitamin D or any other supplements. Let’s bone up (no pun intended) on Vitamin D!

~ Judy Tong, O.D., F.A.A.O.
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

Proper care of contact lenses

contact pictureNext week, the Center for Disease Control and Prevention is sponsoring its first Contact Lens Health Week. Since more than 34 million Americans wear contact lenses, this topic is absolutely important and definitely a little late in coming.

While I would love to say that all of my patients have perfect hygiene habits, many of them do not. I have heard of patients sleeping in their contacts for months on end, using tap water to store them, and cleaning them in their mouths after falling out. Yes, the last one is true

So, after listening to my patients, here is my top ten list for caring for your contacts and your eyes:

  1. Wash your hands before handling your lenses.
  2. Keep your contact lens case clean and let it air dry.
  3. Change your case with every new bottle of solution.
  4. Use name brand solution and never top off your solution (always use new solution!).
  5. Throw your lenses out at the doctor prescribed interval.
  6. Even if your lenses are approved for overnight wear, it is a whole lot safer if you don’t.
  7. The solution may say no rub, rub anyway.
  8. Saline solution is not disinfecting, you need to use a proper solution.
  9. Contact lens solution is not a good rewetting drop. Ask your doctor for a good choice.
  10. Daily disposable contacts are the safest choice for those who swim. Open water and hot tubs are especially dangerous pathogens love these conditions.

The bottom line is that if you follow the rules, contacts can be a very safe and effective way to see better. Just remember to see your doctor every year to make sure that your contacts are still the best choice for your eyes. Your optometrist can be a great resource so make sure to ask questions during your exam and let them know if you are experiencing any difficulties with your lenses.

~ David C. Ardaya, O.D.
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org

Top five vision myths

Courtesy of riekhavoc (caughtup?) on Flickr

Courtesy of riekhavoc (caughtup?) on Flickr

As a doctor of optometry, I hear it all. And with Dr. Google serving as an impromptu family physician these days, myths regarding eye health are bound to circulate. Here are the top vision myths debunked:

  1. Wearing eyeglasses that are too strong or have the wrong prescription will damage the eyes.
    Prescription lenses in eyeglasses alter light rays into the eye. The prescription lenses do not change any part of the eye. In an adult, wearing glasses that are too strong or an incorrect prescription cannot harm the eye, although it may result in eyestrain or a temporary headache. With an incorrect prescription, vision will be blurry, but not harmful to the eye.
  2. Wearing eyeglasses will cause you to become dependent on them.
    Eyeglasses are used to correct blurry vision. Since clear vision with eyeglasses is preferable to blurry vision, one may want to wear eyeglasses more often. With glasses, it may feel that you are becoming dependent on them. However, you are actually just getting used to seeing clearly.
  3. Wearing eyeglasses will weaken the eyes
    Eyeglasses worn to correct nearsightedness, farsightedness, astigmatism, or presbyopia will not weaken the eyes. In addition, glasses will not permanently “cure” these types of vision problems. Wearing glasses will enable clear vision caused by these refractive errors. (There are exceptions – glasses for children with crossed eyes (strabismus) or lazy eye (amblyopia). These glasses are used to help straighten the eyes or improve vision. Not wearing glasses may permanently impair vision).
  4. Using the eyes too much will “wear them out.”
    Eyes are made for seeing and cannot be used too much. We would not lose our sense of hearing by using our ears excessively.
  5. Holding a book too close or sitting too close is harmful to the eyes.
    Many children like to hold books very close to their eyes. Children have excellent focusing ability, so sitting close is normal and safe. Also, both children and adults who are nearsighted may get close to a book to see it clearly. This does not cause or worsen any type of eye problem.

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

A contact lens exam, what’s different?

Photo courtesy of Valley Eyecare Center

Photo courtesy of Valley Eyecare Center

I often get this question from patients: “I can see fine. My contacts are fine. Why do I have to have a contact lens exam?” This is not an unusual conversation in my office. Now is a great opportunity to explain the different tests done in a Contact lens exam.

One important thing we need to understand is that contact lenses are FDA approved medical devices.  They are actually small, very thin, pieces of plastic that sit directly on the cornea. The cornea of the eye is a very small, yet complicated structure that needs to be examined regularly when a patient wears contacts. Misuse of contacts and/or poor fitting contacts can cause serious harm to the health of the cornea and ultimately your vision.

My vision is fine. Why do I need another exam?

There are several tests your optometrist will do to determine that contacts are safe, healthy on your eyes and that the prescription is correct. We measure the curvature of the surface of the cornea – using a Keratometer or a Topographer – to determine the right size of contact to put on. Taking this measurement every year will help ensure that the contacts are not causing any subtle damage to the surface of the cornea. There is also a highly specialized microscope that some doctors are beginning to use that is able to count the number of corneal cells to make sure that they are staying stable while using contact lenses. These tests are early detectors of corneal changes due to the use of contacts that may not initially affect the vision or comfort of your lenses.

The contact lens exam also includes a detailed tear analysis to determine if you have dry eyes or allergy eyes. These common conditions can affect the comfort of your lenses and your vision. There are many different types of materials that contacts are made of and some are not compatible with certain eye surface conditions. For example, someone might need a contact with more water in it, others might need one that transmits more oxygen to the cornea. All of these factor are determined in the contact lens exam.

Next, the contact lens prescription needs to be determined. Due to the fact that that contact lens sits on the eye, not in front of the eye like glasses do, there is actually a different determination of the contact lens prescription that needs to be done in some cases. So, no … the contact lens prescription is not the same as the glasses prescription.

Once all of the parameters of the contact lens is chosen – size, material and optical prescription – the lens needs to be evaluated on the eye. We look at how the lens moves on the eye and how it sits to determine if it is going to be a healthy lens for you. Sometimes, differences in eyelids, blinking and tears can affect how a lens sits on the eye and adjustments might need to be made.

Finally, when your optometrist is happy with the fit and the vision through the contacts, then your contact lens examination is complete. Depending on the difficulty of your prescription, any eye surface disease, such as dry eyes or allergies, and if you are an experienced wearer or not, this process can take from one visit to several. Work with your optometrist during the process so that your can safely wear contact lenses for many years to come.

~ Lisa M. Weiss, O.D.
California Optometric Association
http://www.coavision.org
http://www.eyehelp.org