Four Tips For Buying Sunglasses

4/29/14

May will be here this week, and in Southern California we are looking at bright, sun-filled days with temperatures in the upper 80s and low 90s. This means that thousands will be heading to the beaches or their own backyards to enjoy the warm weather.

Now is the perfect time to review one of the biggest contributing factors to vision loss – sun exposure. And it’s not just about sunglasses, but also brimmed hats.

from esty.com
from esty.com

First let’s talk about sunglasses. There are three things to think about when selecting your sunglasses:
1. Lens tint
2. UV protection
3. Glare
4. Frames

Lens Tint
There is a misconception that the darker your sunglass lens, the better protection for your eyes. No true. The color or darkness of your lens is personal preference and often based on the activity you are doing while wearing sunglasses or the sun conditions. At the beach in bright sunlight you are subject to more reflective light and may prefer dark amber, copper or brown lens, if you are on the ski slopes when the skies are overcast you may prefer yellow or orange lens to increase contrast and fight “flat light.” If you are looking to increase contrast on a partially cloudy day, and if you don’t mind distorted color perception, you might prefer amber or rose lenses.

Other considerations include mirrored sun lenses that can block 10-15% more of the sun’s visible rays, or photochromic lenses that darken automatically when you go outside and then quickly become lighter when you come inside.

UV Protection
While darker lenses don’t offer better eye protection, controlling the UV exposure does. Research has found links that extended exposure to UVA and UVB rays can result in eye damage such as cataracts, photokeratitis and macular degeneration. By wearing sunglasses that block these harmful rays your eyes should remain healthier as you age. Also know that some parts of the country receive more UV rays than others – here is a wonderful chart from The Vision Council to let you see how your location rates.

Glare
Another problem when out in the sun, and especially driving, is glare. Making sure your lenses are polarized is a great help. They work by only letting in specific amounts of light at certain angles and reducing the brightness of that light.

Because I am light sensitive I find I use polarized lenses when I am reading outside is helpful. The reflected light from the page of a book can cause me to squint or fatigue my eyes if I read for a long period of time. The only other option is using a paper-ink e-reader which also helps cut down on glare.

Another way to deal with glare is the use of an anti-reflective (AR) coating on your lenses. It reduces eye stain by preventing light from reflecting off lens surfaces. When applied to the back of your lenses it can help with problems when the sun is behind you or to your side.

Frames
Not all light hits your eyes from directly in front. It can come through the top, sides and bottom of your frames. The smaller the frames, the more unfiltered light makes its way to your eyes. This is where a brimmed hat can help keep the sun coming in from the top while also providing protection for your face.

Fitovers - Auroa in Claret
Fitovers – Auroa in Claret

To provide you with the maximum protection, “fit-over” sunglasses, that you can wear over your regular prescription glasses, are a great idea and more economical. Cocoons Eyewear and Fitovers Eyewear are two of several companies that make them. They filter the light from the top, sides and even below to give you the maximum protection and come in a wide variety of lens colors. It is also nice not to have to get new sunglasses when your eyeglass prescription changes.

Whatever frames you choose make sure they fit properly and will not keep sliding down your nose or fall of when being active. You may even want to purchase a band-style foamed neoprene retainer that attaches at both temples, sometimes known as a gator.

Also remember, it is not just the direct sunlight you need to worry about. Water reflects up to 100% of the harmful UV rays, dry sand and concrete up to 25% and even grass reflects up to 3%.

Susan DeRemerSusan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Corneal Transplant Surgery Options

In this day and age of advancing technology, corneal transplants have changed from a long arduous ordeal to a more simple and precise procedure that offers faster visual recovery.  Instead of replacing the entire cornea for any and all corneal diseases, we now perform disease targeted partial corneal transplants.  If the disease involves the back layer of the cornea, we perform endothelial keratoplasty and replace only the diseased inner layer of the cornea.  Conversely, if the problematic portions are the front layers of the cornea, we perform anterior lamellar keratoplasty.  The co-morbidity and risk of rejection from partial corneal transplants are significantly less than the traditional full thickness transplants.

With endothelial keratoplasty, a small incision, about 4-5 mm is made and a sheet of donor endothelial cells are placed into the anterior chamber of the eye.  A large air bubble is then used to float this sheet up so that it opposes the posterior or back portion of the cornea.  The patient is asked to position face up for 24 hours.  Over this period of time, the cells will “stick” on their own and thus no sutures are required to keep the graft in place.,/span>

Figure 1 - corneal transplant
Figure 1

Anterior lamellar keratoplasty is done for superficial scars and opacities of the cornea or for keratoconus, a genetic degeneration of the cornea that is seen in younger individuals.  In this case, the native endothelial cells of the patient are healthy and therefore are left intact while the remainder of the cornea is transplanted.  This significantly lowers the risk of rejection, which is traditionally a much higher risk in young patients.  Multiple sutures are required to maintain this graft in place however, with the advent of femtosecond laser technology, the wound configuration is made in such a way as to promote rapid healing and visual recovery. (Figure 1)  Sutures are removed at an earlier time than with traditional surgery and the eye is able to undergo visual rehabilitation with glasses or contact lenses in 3-6 months’ time.

Corneal transplantation does not require waiting on a list for a donor to become available like it once did.  There are now multiple excellent eye banks across America that harvest, screen, and distribute donor tissue to surgeons.  This way, tissue is readily available and patients only need to schedule a time based on their own and their surgeon’s time schedule.  Post operatively, patients are asked to return to regular activity with the exception of no heavy lifting or bending for a period of 2 months.  Antibiotic and anti-rejection drops are started immediately after surgery and continued for several months after.  No oral medications aside from the patient’s regular medications are required.

Farid 3.6.14Marjan Farid, MD
Director of Cornea, Cataract, and Refractive Surgery
Vice-Chair of Ophthalmic Faculty
Director of the Cornea Fellowship Program
Associate Professor of Ophthalmology
Gavin Herbert Eye Institute, University of California, Irvine