Trouble understanding visual images and spatial relationships. Many people have vision problems related to conditions such as glaucoma or cataracts. Vision problems related to Alzheimer’s include having difficulty reading and understanding what is written, and judging distance. Some people with Alzheimer’s disease might pass by a mirror and think that the person reflected there is someone else, of they might have trouble reading the face of a clock. A medical professional is best qualified to evaluate these or other vision changes or problems.