Visual Acuity

Visual acuity refers to the clarity or sharpness of vision, typically measured using an eye chart at a standard distance of 20 feet. It is a critical indicator of eye health and function in ophthalmology. The measurement is expressed as a fraction, with the numerator representing the testing distance and the denominator indicating the smallest line of letters that can be read without error. For instance, if someone has 20/20 vision, they can see at 20 feet what a person with normal vision can see at the same distance. Visual acuity depends on the proper functioning of the cornea, lens, and retina, and it can be affected by refractive errors like myopia (nearsightedness) or hyperopia (farsightedness), as well as conditions such as cataracts or macular degeneration. Regular eye exams are essential to monitor visual acuity and detect any changes in vision early.