What type of chart is typically used by healthcare professionals to evaluate visual acuity?

The Snellen chart is the standard tool used by healthcare professionals to evaluate visual acuity. It features a series of letters, usually in decreasing sizes, which patients are asked to read from a designated distance. This method provides a clear measurement of how well a person can see compared to the expected standard vision. The results from the Snellen chart are expressed as a fraction, such as 20/20, which indicates normal vision.

Using this chart allows professionals to categorically assess and document a patient's visual ability, which is crucial for diagnosing and monitoring various eye conditions. The clarity and straightforward nature of the Snellen chart make it a widely accepted instrument in eye exams, as it effectively distinguishes between different levels of visual acuity in a way that is easily interpretable.