acuitet
Acuity, in a general sense, refers to sharpness or keenness of thought, perception, or vision. When applied to vision, it is most commonly understood as visual acuity, which measures the clarity or sharpness of vision. This is typically assessed using a standardized chart, such as the Snellen chart, where an individual attempts to read letters or symbols at a given distance. The results are often expressed as a fraction, like 20/20, indicating normal visual acuity. Higher numbers in the denominator (e.g., 20/40) suggest poorer vision, meaning the individual needs to be closer to see what a person with normal vision can see at a greater distance. Conversely, a smaller denominator (e.g., 20/10) indicates better than normal vision.
Beyond simple visual acuity, the term can also encompass other aspects of visual function, such as contrast