BIO 145: Basic Human Anatomy and Physiology (Backus-Loudoun)

Deafness: "Complete or partial loss of the ability to hear. The deficit may be temporary or permanent. More than 20 million Americans have hearing impairment; most of them are over 65; about 5% are children. Hereditary forms of hearing impairment affect about 1 newborn in 2000. In this population hearing deficits may impair language acquisition and speech. Acquired hearing loss affects the lives of nearly half of all people over 80, in whom it may be a prominent cause of social isolation or depression." Taber's Cyclopedic Medical Dictionary, 2017.

Presbyopia: "The term presbyopia means “older eye,” and is a vision condition involving the loss of the eye's ability to focus on close objects. Presbyopia is a condition that occurs as a part of normal aging. The condition develops gradually over a number of years. Symptoms are usually noticeable by age 40 to 45, and continue to develop until the process stabilizes some 10 or 20 years later. Presbyopia occurs without regard to other eye conditions." Gale Encyclopedia of Nursing and Allied Health, 2018.