näköterävyystestit

Näköterävyystestit, commonly known as visual acuity tests, are essential tools used by eye care professionals to measure how clearly a person sees. They assess the sharpness of vision at various distances. The most widely recognized test is the Snellen chart, which consists of rows of letters or numbers that progressively decrease in size. Individuals are asked to read these characters from a specific distance, typically 20 feet (or 6 meters). The results are usually expressed as a fraction, such as 20/20, where the first number represents the standard testing distance and the second number indicates the smallest line the person can read at that distance. A 20/20 vision signifies normal visual acuity.

Other types of visual acuity tests exist, such as the Tumbling E chart for individuals who cannot read or recognize letters, and the Landolt C chart, which uses broken rings with gaps in different orientations. For younger children, picture charts with familiar images are often employed. These tests can detect refractive errors like myopia (nearsightedness), hyperopia (farsightedness), and astigmatism, as well as more serious underlying eye conditions. Regular visual acuity testing is crucial for maintaining good eye health and ensuring optimal vision throughout life, enabling timely intervention if any issues are detected.