DAWN: Low vision is really a lot of different things. The most common way to define it would be to say that it's vision that's not adequate for a person's needs.
MARY: I got 10 after 5.
DAWN: That might mean different levels for different people.
MARY: I think.
DAWN: One good example is the man sitting on a park bench reading a newspaper but he's got a white cane next to him. Well, if he can read a newspaper with no glasses, why should he need a white cane? Well, he may just have very, very small visual fields and so he may have a big enough field to read but he may not be able to walk around the street without harming himself without the aid of that cane. You just come all the way up in there with your forehead. Good. The diseases that cause low vision-- the most common one we see here is macular degeneration. We see several patients with glaucoma--end-stage glaucoma-- where their visual field is severely limited. Retinitis pigmentosa is the leading cause of hereditary blindness in this country--that's another common one. In children, we see a lot of albinism. Diabetic retinopathy is another very common cause of vision loss.
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Mary's condition is age-related macular degeneration. It's a retinal disease so that means it affects the very back part of the eye. The retina is to the eye what film is to a camera-- so the retina captures the light and makes an image so that the brain can interpret it. And in a lot of people, in their older years, they develop a degeneration of that central area that's responsible for your fine, detailed central vision. And that creates a large scar back there. A lot of patients with central vision loss will also actually look off to the side of what they're trying to look at because that moves the scar out of the way and lets the image fall in the healthy part of their retina and lets them see it in greater detail than they could looking through the scar. My very first low vision patient, when I was a student, wouldn't look at me. And I kept telling her, "But the chart's over here." And she's like, "But I can't see it if it's over there." And so that was my first experience with people who do what we call eccentric viewing. So they use their healthiest part of their retina to look even though it's not the part we normally would use. And so that gives you the impression that they're not looking at you when they really are. Mary has that little circular lens on. And that's another form of a microscope that we've applied to her regular glasses so she wouldn't have to change pairs all the time.
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We sent her home with a loaner telescope to try at home to see how that was work and it was one that focused far away and up close. And then we sent her home with a bunch of tips about how important lighting is and how important good contrast is. If you're having difficulty seeing things, the last thing you want to try to see is a whole bunch of white things sitting on top of each other.
INSTRUCTOR: Does that help you see the plate easier?
DAWN: The importance of seeing a low vision specialist is that a lot of doctors don't offer the same degree of visual rehabilitation that a low vision specialist does. In a low vision exam, that doctor has a lot of low vision devices stocked and they have special tests for evaluating the needs of people with low vision and have staff that are trained to work with people with low vision. So--
MARY: I can read the fourth line there.
DAWN: It's nothing more frustrating to me than the patient who comes to see me for a low vision eval and I set them up with a pair of microscopes or something and they're able to read again. And they're, like, "Why didn't somebody tell me this 10 years ago?" I have no idea why nobody told them this 10 years ago. What they usually tell me is, "My doctor said nothing could be done, but they didn't tell me about you."