What is the common range of soft contact lens powers?

What is the common range of soft contact lens powers?

• A. +6 to -12.00 D
• B. -0.50 to +0.50 D
• C. +8 to -14 D
• D. 0 to ±6 D

Answer: (A)

Soft lens powers are given in diopters and must cover the range of refractive errors a clinician typically encounters. Negative numbers correct myopia, positive numbers correct hyperopia, and zero means no correction. In standard practice, the common stock range for soft lenses spans from about -12.00 D up to +6.00 D. That means a patient with strong myopia could be fitted with lenses around -12.00 D, while someone with strong hyperopia could be fitted up to about +6.00 D. Other options propose narrower ranges or limits beyond what is usually stocked in typical lines, so they don’t represent the broad, standard coverage. Therefore, the range that matches common availability is from -12.00 D to +6.00 D (written as +6 to -12 D).

Soft lens powers are given in diopters and must cover the range of refractive errors a clinician typically encounters. Negative numbers correct myopia, positive numbers correct hyperopia, and zero means no correction. In standard practice, the common stock range for soft lenses spans from about -12.00 D up to +6.00 D. That means a patient with strong myopia could be fitted with lenses around -12.00 D, while someone with strong hyperopia could be fitted up to about +6.00 D. Other options propose narrower ranges or limits beyond what is usually stocked in typical lines, so they don’t represent the broad, standard coverage. Therefore, the range that matches common availability is from -12.00 D to +6.00 D (written as +6 to -12 D).