S on eye report indicates which aspect?

• A. The degree of nearsightedness or farsightedness
• B. Astigmatism
• C. Axis
• D. Color vision

Answer: (A)

The S on an eye report represents the spherical component of the prescription, which shows how strongly the eye needs to be corrected to focus light on the retina. This value directly reflects the degree of nearsightedness (myopia) or farsightedness (hyperopia): negative numbers mean myopia, positive numbers mean hyperopia, and larger magnitudes indicate stronger correction. Astigmatism and axis are described separately by the cylinder and axis values, and color vision is tested with a separate procedure, not captured by the spherical power. So the S value indicates the overall spherical refractive error—the degree of nearsightedness or farsightedness.