The Eye Exam It was a sunny day in 2005, and time for Ericâs annual eye exam. Dr. Tim flipped through his charts. âYou know, we really should measure your visual fields. Itâs been at least ten years since you had that done!â âI hate them!â Eric grumbled. âI get disoriented and, anyhow, we already know I have a large blind spot.â He raised his hand, squinting through one eye. âHere. I canât see my finger here.â âI know.â Dr. Tim was sympathetic. âBut werenât you just telling me you havenât seen stars for a while? Itâs important. You had that tumor on your pituitary gland. Your optic nerves cross in that area, right in front of the pituitary, so if anything is happening again weâd probably notice it first by changes in your eyesight. It really is important!â An hour later, Eric was seated in front of a large white screen, staring intently at a light in the middle. âKeep looking at that light, so your eyes donât move. If you see another light anywhere else, push this button.â Eric began the test by focusing on the light he saw in the center. The machine then successively displayed points of light of varying intensity in different places around the entire visual field. When Eric saw the peripheral light, he pushed a button. He did his best to detect the flashes, but realized he was probably missing some. The machine mapped out where he could see and where he could not. Dr. Tim looked at the printout. His face grew serious. âEric, we have a problem. You have limited peripheral vision, and itâs bad enough that I donât think you should be driving! This looks to me like something called retinitis pigmentosa. We should refer you to a specialist.â He pulled out more papers. âHere, look at this. Here are your visual fields. The numbers show how well you can see in that area of your eye, and in the graph on the right the darker the box is the less you can see. Now here are a normal personâs visual fields. Do you see the difference?â
1. How do your eyes work? What is the difference between focal vision and peripheral vision?
2. What is the anatomy around the pituitary gland? Why are the optic nerves likely to be affected by pituitary tumors?
3. Eric has retinitis pigmentosa In this disease pigments lining your eye gradually break down, so you canât sense the light that hits your eye. Why do you need the pigments in order to see the images and light?
The Eye Exam It was a sunny day in 2005, and time for Ericâs annual eye exam. Dr. Tim flipped through his charts. âYou know, we really should measure your visual fields. Itâs been at least ten years since you had that done!â âI hate them!â Eric grumbled. âI get disoriented and, anyhow, we already know I have a large blind spot.â He raised his hand, squinting through one eye. âHere. I canât see my finger here.â âI know.â Dr. Tim was sympathetic. âBut werenât you just telling me you havenât seen stars for a while? Itâs important. You had that tumor on your pituitary gland. Your optic nerves cross in that area, right in front of the pituitary, so if anything is happening again weâd probably notice it first by changes in your eyesight. It really is important!â An hour later, Eric was seated in front of a large white screen, staring intently at a light in the middle. âKeep looking at that light, so your eyes donât move. If you see another light anywhere else, push this button.â Eric began the test by focusing on the light he saw in the center. The machine then successively displayed points of light of varying intensity in different places around the entire visual field. When Eric saw the peripheral light, he pushed a button. He did his best to detect the flashes, but realized he was probably missing some. The machine mapped out where he could see and where he could not. Dr. Tim looked at the printout. His face grew serious. âEric, we have a problem. You have limited peripheral vision, and itâs bad enough that I donât think you should be driving! This looks to me like something called retinitis pigmentosa. We should refer you to a specialist.â He pulled out more papers. âHere, look at this. Here are your visual fields. The numbers show how well you can see in that area of your eye, and in the graph on the right the darker the box is the less you can see. Now here are a normal personâs visual fields. Do you see the difference?â
1. How do your eyes work? What is the difference between focal vision and peripheral vision?
2. What is the anatomy around the pituitary gland? Why are the optic nerves likely to be affected by pituitary tumors?
3. Eric has retinitis pigmentosa In this disease pigments lining your eye gradually break down, so you canât sense the light that hits your eye. Why do you need the pigments in order to see the images and light?
