Used to measure visual acuity?

Used to measure visual acuity?

• A. Snellen chart (SC)
• B. Refraction test
• C. Cover test
• D. Ophthalmoscopy

Answer: (A)

Visual acuity is the ability to resolve fine detail at a distance. The Snellen chart is designed for this purpose: it uses lines of letters that shrink in size and asks you to read the smallest line you can at a standard distance. The result is written as a fraction (for example, 20/20), indicating the distance at which a person with normal vision can read the same line. This direct assessment of how clearly distant details are seen is why the Snellen chart is the go-to tool for measuring visual acuity. The other tests serve different purposes: a refraction test determines the corrective lens power needed but doesn’t itself quantify acuity; a cover test checks eye alignment; ophthalmoscopy examines the retina and optic nerve.

Visual acuity is the ability to resolve fine detail at a distance. The Snellen chart is designed for this purpose: it uses lines of letters that shrink in size and asks you to read the smallest line you can at a standard distance. The result is written as a fraction (for example, 20/20), indicating the distance at which a person with normal vision can read the same line. This direct assessment of how clearly distant details are seen is why the Snellen chart is the go-to tool for measuring visual acuity. The other tests serve different purposes: a refraction test determines the corrective lens power needed but doesn’t itself quantify acuity; a cover test checks eye alignment; ophthalmoscopy examines the retina and optic nerve.