Age-related macular degeneration (AMD) is a degenerative disease, typically associated with older age that causes a large blind spot in the central visual field. When this vision loss hits both eyes, you’re apt to have trouble reading or fixating on something. One signal of this disease: you find you’re forced to turn your head when you need to view something.
This disease is characterized by a slowly degenerating retina at the macula, which is responsible for sharpness of vision. With age-related macular degeneration, you’re apt to show signs of what is called the filling-in phenomenon. You actually begin to fill in the blind spots triggered by this disease based on past visual experience. Because it’s tough to fixate on objects with your central retina in AMD, you’re likely to move your eyes or head slightly to the side to compensate for the vision loss. This way, you can “place” the object you wish to catch with the intact regions of the retina outside of the edge of the damage. This new retinal location that you’re likely to use to view objects is what scientists call the preferred retinal location.
Unfortunately, it’s possible to choose the wrong spot of the retina as your preferred retinal location. This is especially so if you’re using intact tissue to the right or left of your central blind spot. However, reading requires eye movements from left to right or, depending upon your culture, from right to left, so that the blind spot gets in the way when you move from word to word during reading.
To bypass the blind spot, or scotoma, that is hampering your reading ability, it might have been better to choose a preferred retinal location above or below the word you are trying to read. The best place for a preferred retinal locus is the field below or above fixation. In other words, practice moving your eyes slightly below or above the reading line. Reading then becomes much easier because you use intact retinal tissue which facilitates reading. Your scotoma then doesn’t get in the way. This approach was pioneered by the Swedish scientists Drs. Ulla and Sven Erik Nilsson.
So with macular degeneration, a little training can help you adapt to the best possible preferred retinal location for reading, which is otherwise blocked by a centrally located blind spot.