látóélességet

Látóélesség, commonly referred to as visual acuity, is a measure of the sharpness or clarity of vision. It describes the ability of the eye to distinguish fine details and shapes. Typically, látóélesség is measured using standardized charts, such as the Snellen chart, which features letters or symbols of decreasing size. The patient's ability to correctly identify these characters at a specific distance is recorded as a fraction, for example, 20/20 (or 6/6 in metric countries). This notation signifies that the individual can see at 20 feet what a person with normal vision can see at 20 feet. A lower number in the denominator, like 20/40, indicates poorer vision, meaning the person needs to be closer to see what a person with normal vision can see from further away. Conversely, a smaller fraction, such as 20/10, represents vision sharper than average. Látóélesség can be affected by various factors, including refractive errors like myopia (nearsightedness) and hyperopia (farsightedness), as well as conditions such as astigmatism, cataracts, and diseases affecting the retina or optic nerve. It is a fundamental component of comprehensive eye examinations and plays a crucial role in diagnosing and monitoring eye health.