For low vision specialists and those who consult them
Different parts of the retina are used for different tasks
September 2, 2010Posted by on
I suppose there’s no point in having a blog if you don’t occasionally use it for self-promotion, so here’s a link to a paper we have just had accepted in Investigative Ophthalmology and Visual Science.
In it, we asked people with macular disease to observe a point target, and used the MP-1 microperimeter to determine which part of the retina people used to do this. We then asked the same people to look at some words which appeared on the same screen. By using some quite advanced statisics, we compared whether the same part of retina was used for both tasks.
We found that all of our subjects used different parts of the retina for these two tasks. Often they were not very far apart, but it was statistically clear that they performed these tasks differently.
Why does this matter? Well, it teaches us a little about eccentric viewing in macular disease, and shows that people don’t necessarily do the same thing when looking at a word as when they look at a target. It means that we can’t really assess how well people use eccentric viewing if we just ask them to look at a light and check which bit of retina they use for that, for example. It also shows that the MP-1 microperimeter can be used for fixation analysis in this way.
Any comments welcomed!