Central visual acuity refers to the ability of the visual system to discern fine distinctions in the environment as measured with printed or projected visual stimuli. The presence of excellent visual acuity tells the examiner that the ocular media are clear, the image is clearly focused on the retina, the afferent visual pathway is functioning, and the visual cortex has appropriately interpreted signals received. Measurement of visual acuity is a most sensitive test of the integrity of the visual system and fulfills all standard criteria of a good screening test: (1) there is minimal cost or risk to the patient; (2) measurement can be performed quickly and easily with little or no examiner training; (3) there is a high prevalence of detectable abnormalities; and (4) abnormalities are most often amenable to treatment.
Copyright © 1990, Butterworth Publishers, a division of Reed Publishing.