Sensory Changes in Aging

Age-related sensory change is usually gradual. The clinical concern is not simply reduced sight, hearing, smell, touch, or balance; it is the loss of information needed to move safely, communicate accurately, manage medications, and recognize danger. Vision commonly becomes less sharp in dim light. Contrast sensitivity, glare tolerance, depth perception, and colour discrimination also decline. A dark rug on a dark floor, a clear medication bottle, or a poorly lit stair edge may become difficult to detect even when the person can still read an eye chart reasonably well. These changes increase fall and medication-error risk. Presbycusis is permanent bilateral sensorineural hearing loss caused by degeneration of cochlear hair cells and auditory nerve fibres. High-frequency sounds are often lost first, so consonants such as s, f, t, and sh become difficult to distinguish. The person may hear that someone is speaking but not understand the words, especially in a busy dining room or hallway. Reduced smell and taste can decrease appetite and make spoiled food harder to detect. Reduced tactile sensation, particularly when diabetes or peripheral neuropathy is also present,...