How is the optical power of a lens commonly described?

The optical power of a lens is commonly described in diopters. This unit measures the ability of a lens to bend light, which is crucial for determining how effectively the lens can focus images on the retina. A lens with a higher power in diopters signifies a stronger lens that can bend light more sharply, making it suitable for correcting vision impairments.

Using diopters allows optometrists and eyecare professionals to prescribe lenses that compensate for individual visual needs, whether for nearsightedness, farsightedness, or astigmatism. This standardized measurement provides a clear indication of the lens's strength, which is essential for proper prescription and alignment.

Millimeters and inches are measurements of length and are not used to express optical power, while degrees pertain to angular measurements and do not apply to the power of lenses in terms of refraction. Thus, diopters is the correct unit of measurement for the optical power of a lens.