The Amsler grid is used to evaluate visual field deficiencies in how many degrees of central vision?

The Amsler grid is a clinical tool primarily used to assess central vision and identify potential visual field deficiencies related to conditions such as macular degeneration. It serves to check for any distortions or blind spots in a patient's central vision. The grid typically covers a visual field of approximately 20 degrees of central vision. This means that patients focus on a central point in the grid while observing surrounding lines, which allows for detection of any areas where vision may be compromised within that 20-degree radius.

Other options may suggest different radii, but the Amsler grid specifically targets the central 20 degrees, aligning with its intended use in evaluating central vision specifically. Thus, the choice indicating 20 degrees accurately reflects the function and application of the Amsler grid in clinical practice.