acuité

Acuité is a French noun meaning sharpness or clarity of perception. In everyday language it can refer to the sharpness of senses, the acuity of observation, or mental sharpness. The term derives from Latin acuitas, from acutus "sharp" and is used in both clinical and non-clinical contexts to describe how clearly a person perceives details.

In ophthalmology, acuité visuelle denotes how well the eye resolves fine detail at a given distance. It is commonly assessed with optotype charts such as the Snellen chart or logMAR tests. In many countries, normal vision is described as 20/20 (decimal 1.0; logMAR around 0.0); poorer acuity is expressed as a fraction or as a higher logMAR value. Visual acuity depends on refractive status, media clarity, and retinal or neural integrity, and can be improved with corrective lenses or surgery.

Acuité can also describe auditory, tactile, olfactory, or gustatory sharpness. Acuité auditive refers to the threshold of hearing—how softly a sound is detected. Tactile acuity measures the ability to discern textures or two-point discrimination. Olfactory and gustatory acuity describe the sensitivity of smell and taste. Across senses, acuity is influenced by age, disease, attention, and environmental factors.

In psychology and education, acuité intellectuelle or cognitive acuity informally denotes mental sharpness, processing speed, and problem-solving ability, but is not a single standardized medical metric. Clinicians typically assess cognitive function with standardized tests rather than a single acuity score. The concept remains a general marker of perceptual or mental sharpness rather than a precise measurement.