Peter Bex, Ph.D.

Answer: People who are losing their vision from diseases such as macular degeneration automatically create ways to compensate for their vision loss. Sometimes those unconscious adjustments are very useful, while other times they can make processing visual information from the environment even more difficult. We aim to understand the adjustments people make, and suggest changes if the adjustments  are not helpful.

We begin by comparing the visual behavior of people with normal vision and those with low vision in real-life situations, observing differences in behavior undertaking similar tasks. From those observations we can make recommendations that translate into new devices, adaptive training programs or modifications in work or living environments.

For instance, we are trying to understand why people with macular degeneration walk more slowly and trip and fall more frequently when walking down a hallway than normally sighted people. By attaching a small specialized camera, known as a mobile eye tracker, under the eyes of normal subjects and subjects  with macular degeneration, we are able to follow eye movements as they walk down a hallway. We have found that people with macular degeneration make many times more eye movements than those with normal vision. They are constantly looking at the walls, the corners and the floor as they make their way to the end of the corridor. Normally sighted people, on the other hand, make a direct line to the hallway’s end with only an occasional extraneous glance. We believe that this constant shifting eye movement may significantly slow a person down and actually prevent him or her from processing well enough to see objects that could make them trip or fall.

This kind of information may help us suggest new behaviors that could help a person with low vision a compensate. For instance, we might encourage longer, slower scanning of the hallway before and during their trek. While counterintuitive, it might increase visual comprehension of the entire space and increase walking speed.

One of our post-doctoral students has come to just such a conclusion in one study of reading and macular degeneration. He found that if people with macular degeneration read each word and scan lines of type slowly, they actually increase reading efficiency and speed because more information is obtained from each fixation.

Simply put, our purpose is to maximize a person’s remaining vision to give him or her the fullest possible life.