Each of the special senses can be expected to decline in some way over time.

Olfactory receptors are reduced in number and olfactory glands decline in activity. Both changes reduce olfactory acuity. Gustatory sense declines with a decline in the number of taste buds and taste receptors. Vision suffers from a loss of retinal function, clouding of lens and cornea, and loss of lens elasticity, leading to senile hyperopia (presbyopia). Hearing declines due to accumulation of cerumen, scarring of the tympanum, arthritis of the ossicular chain, and loss of proximal hair cells in the organ of Corti, leading to high-tone deafness. Balance declines due to nerve problems, fluid problems, and vascular problems, leading to faulty or delayed vestibular information. That decline coupled with a sluggish and weak motor response increases the risk of falls and consequent trauma.