- 1. Sharpness, clearness, distinctness. 2. Severity. [thr. Fr., fr. L. acuo, pp. acutus, sharpen]- resolution a. detection of a target having two or more parts, often measured by using the Snellen test types; indicated by two numbers: the first represents the distance at which an individual sees the test types (usually 6 m or 20 ft), and the second, the distance at which the test types subtend an angle of 5 min.; e.g., vision of 6/9 indicates a test distance of 6 m and recognition of symbols that subtend an angle of 5 min. at a distance of 9 m. SYN: visual a..- spatial a. detection of the shape of a test object; e.g., perceiving polygons of the same size but with different numbers of sides.- stereoscopic a. the detection of differences in distance by superimposition of slightly different retinal images into a single image to the brain.
* * *acu·ity ə-'kyü-ət-ē n, pl -ities keenness of sense perception <\acuity of hearing> see VISUAL ACUITY
* * *n.
* * *acu·i·ty (ə-kuґĭ-te) [L. acuitas sharpness] clarity or clearness, especially of the vision.
Medical dictionary. 2011.