Translation of "visual acuity" into Icelandic

Visual acuity can be measured in the following ways: • Snellen Test: This is the traditional method, created by Herman Snellen in 1862. It involves identifying letters or symbols (Snellen’s E) on a chart from a specific distance. The standard is 20/20 vision, meaning you can see at 20 feet what a person with normal vision can see at 20 feet. If someone has 20/40 vision, they must stand 20 feet away to see something that a person with normal vision can see from 40 feet. • Grating Acuity: This method measures the smallest level of detail a person can resolve using sinusoidal gratings (light and dark bars). The key parameter here is spatial frequency, which measures how many cycles (from light to dark) occur per degree of visual angle. This method is highly accurate for testing contrast sensitivity and fine detail vision.