Age-related macular degeneration typically affects both eyes, but it is possible the eye disease may start in one eye and then progress to affect the other eye as well. Someone with unilateral (one-sided) AMD is more at risk of it becoming bilateral. Dry AMD is more difficult to discern early on and may affect one or both eyes, with the good eye compensating for the weaker, diseased eye. The patient may not realize something is wrong until there are significant vision changes.
The bottom line: It's more common for AMD to be bilateral or affect both eyes. The disease may not progress at the same pace in each eye, and it's possible to develop dry AMD in one eye and wet AMD in the other.