Vision Loss Simulators

It is difficult for the normal sighted person to understand the vision loss suffered by someone with AMD. Following is an excellent way to simulate this vision loss written by Dr. Mark Wilkinson, the co-author of our book, Protect Your Sight.

Vision Loss Simulators
by Mark Wilkinson, O.D.

I am often asked to describe how a person with macular degeneration sees. Many pictures are available that attempt to demonstrate loss of vision from macular degeneration. These pictures often show a central blind spot (scotoma) with the surrounding area appearing fairly clear. These pictures imply that if you just move the blind spot out of the way, everything will be clear. Unfortunately, this is not the case. Our peripheral vision is designed to provide us with vision under low light conditions. Our peripheral vision is not capable of the same level of detail vision as our macula is without the use of optical or electronic magnification. In addition, with vision loss from macular degeneration, there is commonly a decrease in contrast sensitivity. The reduced contrast sensitivity makes it more difficult to see details when looking at faces or reading a newspaper.

A simple way to simulate the vision loss in AMD can be accomplished by looking through Ziploc® bags (I have not tested other brands of these bags, but they are likely about the same). To simulate early vision loss, look through a Ziploc® sandwich bag. The sandwich bag will decrease vision by a factor of 2. Thus a person with normal 20/20 vision would see 20/40 though the bag. Folding the bag over on top of itself or looking through 2 bags, decreases the vision about 4x, like going from 20/20 to 20/80 vision. Looking through a 2 gallon Ziploc® storage bag decreases vision just over ten times, like going from 20/20 to a little poorer than 20/200 vision. If you fold this big bag over and look through it, your vision will be decreased 20 times or from 20/20 to 20/400. These simulations will work equally well for distance and near visual tasks and are more realistic than other simulations. The method also simulates the vision loss from a cataract or a scar in the cornea.