Focusing becomes less accurate. Sensitivity to glare increases. It is more difficult to make adaptations to darkness. The ability to see colors changes with age. As you grow older, the lens of the eyes yellow.
Trouble can occur with the blue end of the light spectrum.
An elderly person may have trouble discriminating between shades of blues and between blues and greens. Red and yellow pills, for example, are easier for an elderly person to see than blue or blue green. Some things can be done to compensate for these visual difficulties. Other than wearing glasses, increasing illumination to high levels helps older people considerably. When there is hearing loss it is usually in the high frequency range resulting in the inability to hear high pitched sounds.