Can eye color affect your vision?

 

Courtesy of Felix Leupold on Flickr

Courtesy of Felix Leupold on Flickr

During my 20+ years of providing clinical care, my patients have asked me a variety of questions regarding their eyes. One of the inquiries that has come up recently is, “I heard that having different eye colors can affect your vision…is that true?”

Well, there certainly has been much written about, debated over, and researched on this very topic. We know that the iris is what gives a person their eye color. There are numerous eye colors and variations thereof. They span from the lightest of blue, to green, to a mixture of hazel, to the darkest of brown, and even violet like that of the late Elizabeth Taylor. Most of us would agree that some of us are more attracted to one eye color over another, so maybe having a particular eye color confers some advantages.

From a vision clarity standpoint, people with varying shades of blue eyes to brown eyes can see equally well. With that said, there are some plusses and minuses in possessing a particular eye color. What is known from an “evidence based” perspective is that individuals with light eyes (blue) tend to be more light sensitive. I often impart this analogy to my patients. If we think of the colored iris as a window covering, more light will be allowed to come through a window to light up a room with a light blue curtain as compared to an opaque brown one. So much the same occurs with a light colored iris. They just have less pigment to block out or reflect back the light. In fact, this may be one of the reasons why an individual with light eyes may be more at risk for developing macular degeneration. Recommendation have been made for patients with light eyes to wear UV protective eyewear, UV coated contact lenses, or even opaque colored contact lenses.

It is also a little known fact that dark eye colors (brown) can withstand high glare situations better than light eyes. Dark eyes have the ability to absorb more light and allow less light to get reflect. My patients with dark eyes are not as bothered by driving at night in the midst of annoying glare from headlights of other cars.

So to circle back to the question, “I heard that having different eye colors can affect your vision…is that true?”

It can be answered with a “YES,” but honestly, the difference is so ever subtle.

~ Judy Tong OD, FAAO
California Optometric Association
http://eyehelp.org
http://www.coavision.org

Color blindness – the causes and the effects

When we think of someone being color blind, we may think that he sees the world in black and white, or shades of gray.  But that is extremely rare.  In fact, almost 8% of men have some form of color vision deficiency where certain colors are more difficult to distinguish, or do not appear as vivid as other colors.  (Perhaps that explains the questionable wardrobe choices my husband sometimes makes.)

What causes it?

Most cases of color vision deficiency are inherited and passed down from the mom.  The photoreceptors in the retina responsible for color are called cones.  Each cone is sensitive to a certain color, in particular, red, green or blue.  If a person has inherited a recessive gene that causes one or more of the cones to be absent or to not function properly, then he will have abnormal color perception.

Photo courtesy of entirelysubjective on Flickr

Photo courtesy of entirelysubjective on Flickr

Some cases of color vision deficiency are acquired later in life as a result of a disease.  More common causative diseases are glaucoma, macular degeneration, and diabetes.  If you notice a change in your color vision, make sure to be evaluated by your optometrist. For eyecare providers, we tend to distinguish color vision deficiency into two broad categories.  Red-green and blue-yellow.  Red-green is inherited and the most common deficiency.  Those with this defect can still see red and green, but the colors are more difficult to distinguish and they may not appear as vivid as to the normal eye.  For example, red and green signal lights may look the same.  One may appear brighter but the lights may both look white.  (For this reason, I’m not a fan of the horizontal traffic lights in some smaller towns.)  Most people who have color vision deficiency have a mild form and are not disabled by this condition.

The other form of color deficiency is blue-yellow where patients have a difficult time distinguishing blue from green or yellow from violet.  This is less common and is usually caused by certain eye diseases.  Unfortunately, for many of these patients, color deficiency is just one visual problem among others.  These patients may also suffer from dimming of vision or distortion of vision.  Often times, bright lighting is helpful for these patients, and occasionally tinted lenses. 

How can I help someone that’s color deficient?

Of course, a comprehensive eye examination is important to rule out any causes of color vision deficiency other than genetics.  This also helps to determine the severity.  Most color deficient individuals carry on like normal without it interfering with their daily lives.  A helpful tip would be to not use the colors red and green as markers because the two colors may appear very similar.  Blue and red will be easier to distinguish.  Unfortunately, those with color vision deficiency should avoid careers that require distinguishing color differences such as airplane pilots, paint mixer, interior designer, etc.

Recently, new developments in tinted lenses have been able to allow some color vision deficient patients be able to see colors they have never seen before.  Sounds promising!

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

Eye color – Did you know?

1) How is eye color determined?

   Eye color is determined by two distinct factors.

  • The pigmentation of the eye’s iris – The iris is a muscle and the colored part of the eye. The amount of melanin present determines eye color.
  •  The scattering of light in the stroma of the iris – Rayleigh scattering is a similar phenomenon that accounts for the blueness of the sky. Blue and green pigments are not present in the iris of humans or ocular fluid.

2) Does eye color change with age?

Photo courtesy of Javier Manso on Flickr

Photo courtesy of Javier Manso on Flickr

  • Yes. Most babies with European ancestry have light-colored eyes before the age of one. As a child grows, melanocytes produce melanin. Melanocytes are cells found within the iris of human eyes. Most eye color changes occur when the child is around one year old, however it can happen up to three years of age.
  • Eye color (lightening or darkening) may change with age. This occurs in 10 to 15 percent of the population. However, if your eye color changes dramatically as an adult, it is important to schedule an examination with your eye doctor. Eye color changes may indicate certain diseases, such as Fuch’s heterochromic iridocyclitis, Horner’s syndrome or pigmentary glaucoma.

 3) Is it possible to see emotions such as anger or love in the eyes?

Yes. Certain emotions can change both the pupil size and the iris color. Pupil size gets larger in dimmer lighting and smaller in brighter lighting. When pupil size changes, pigment in the iris compress or spread apart, which can change the eye color.

4) What makes eyes green?

The color of green eyes is not a result of iris pigmentation. Green eyes are due to a combination of amber or light brown pigmentation of the stroma. There is a low or moderate concentration of melanin. The green appearance is due to the Rayleigh scattering of reflected light.

5) What can I do to change my eye color?

Color contact lenses are available if you want to change your eye color. There are even colored contact lenses with patterns for occasions such as Halloween. Since contact lenses are medical devices, visit your doctor of optometry for a contact lens fitting.

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

The SCARY… and fun truth about colored contact lenses

Colored contact lenses are a popular topic this time of year as many people prepare their Halloween costumes. How fun is it to have a cool accessory like tiger eyes, cat eyes or red or white eyes to complement the most creative of costume? Colored contacts are a great fun option.  There are also many people who like to wear colored contact lenses daily to make their eyes more blue, more green, more brown or a different color all together!

Courtesy of therefromhere on Flickr

Courtesy of therefromhere on Flickr

However, most people do not realize that even contacts worn for cosmetic purposes still pose a potential health risk for the eye if not properly fitted. This is true even if there is no prescription on the lens.  Contact lenses are classified as “medical devices” with the FDA.  Regardless of a corrective prescription, contacts are plastic on the surface of the eye and need to be fit properly and be taken care of properly to lessen the chance of vision threatening infections such as corneal ulcers.

Doctors of optometry perform additional tests above and beyond the glasses and eye health examinations when fitting contacts. We evaluate the size and shape of the cornea, the health of the tear layer and the fitting relationship between the cornea (the outer surface of the eye where the lens sits) and the contacts lens to insure the safest most appropriate lens for each individual patient.  We also educate patients on the best cleaning and wearing regimen for the them.  This greatly reduces any complications associated with contact lens use.

Buying contact lenses without a doctor’s prescription is something that happens with colored contacts often.  This practice leads to rise in vision threatening conditions that could be prevented with a proper contact lens examination. So, buy a different kind Halloween contact lens for each Halloween party this season, but get a prescription first!

~Lisa Weiss, OD, MEd, FCOVDCalifornia Optometric Association
http://www.coavision.org

Should I get contact lenses? Quick guide to help you decide!

Prescription contact lenses can provide the freedom and comfort to perform a number of activities that cannot be achieved in glasses.

  • The most common example is sports. For those instances where you know you will be running or jumping for extended amount of time and hopefully breaking a sweat at the same time, contact lenses are an ideal choice for vision correction. No need to worry about your frames slipping off your nose or blocking your peripheral vision. Contacts can provide you with crisp and clear vision throughout your entire visual field so you can focus on being your best.
Courtesy of nikozz on Flickr

Courtesy of nikozz on Flickr

  • Another great example is for social events or gatherings where you know there will be cameras everywhere. This can range from brides-to-be prepping for their big day to just spending a night out with friends. When you know you want to look your best in the photos commemorating important times in the lives of your family and friends, contact lenses are the best accessory you could ask for!
  • Similarly, prescription color contact lenses can give you that extra pizzazz when you want to be a little different. Whether you are just adding a little blue or green to match your outfit or a purple or gray tint to draw some extra attention to your face, prescription color contacts can be a great choice to help you stand out in a crowd.
  • I personally choose to wear my prescription contact lenses on days when it is raining or cold. That way I can avoid having rain drops on my glasses or having my lenses fog up for 30 seconds or more when I go indoors in the winter time.
Courtesy of maikel_nai on Flickr

Courtesy of maikel_nai on Flickr

  • The best thing about contact lenses is the new technology used in the current manufacturing processes of prescription contact lenses. This allows your optometrist the ability to fit nearly any prescription you can imagine in materials that are approximately 10 times better than what we used only a few years ago! Today’s prescription contact lenses are available in aspheric designs to help you see more clearly and with UV blocking filters to help protect your eyes throughout the day.

If you think contact lenses may work for you, call your optometrist today to schedule a contact lenses fitting.

~Ranjeet S. Bajwa, OD