Visual potential and its use in geriatric mental hospital patients.

Seeing guides our responses through most of our waking hours. Clear vision is not indispensable to efficient functioning, but it is a characteristic of the normally fortunate as contrasted with the handicapped. As eyes age? normal physiologic alterations produce changes in the limits of natural clear vision. The range of accommodation, which makes possible the adjustment of focusing of the eyes for different distances, decreases fairly regularly from earliest childhood until it is completely lost in old age. This association of visual changes with aging is recognized by the term “presbyopia”-a word signifying “old eyes.” The presence of presbyopia indicates the need for bifocals, or at least glasses for close work, as so frequently happens in the forties. Some older people reject such assistance and assert that they see very well without ocular correction. Their criterion of satisfactory vision is a subjective one. Measurement of visual acuity in such patients may reveal limitations (often correctable by glasses) which completely alter previous conclusions concerning their visual status and their potential visual efficiency.