Which best describes the lens?

Which best describes the lens?

• A. Transparent, bi-concave
• B. Transparent, plano
• C. Transparent, bi-convex
• D. Opaque, convex

Answer: (C)

The lens is a transparent, bi-convex structure that focuses light onto the retina. It must be transparent to let light pass through to the photoreceptors, and its bi-convex shape—curved outward on both sides—provides additional refraction beyond the cornea, helping fine-tune focus. The lens also changes shape during accommodation to switch between near and far vision, thanks to the ciliary muscles and zonular fibers. Descriptions involving a flat (plano), concave, or opaque lens wouldn’t support proper light transmission or the necessary optical refraction. Therefore, the best description is transparent, bi-convex.

The lens is a transparent, bi-convex structure that focuses light onto the retina. It must be transparent to let light pass through to the photoreceptors, and its bi-convex shape—curved outward on both sides—provides additional refraction beyond the cornea, helping fine-tune focus. The lens also changes shape during accommodation to switch between near and far vision, thanks to the ciliary muscles and zonular fibers. Descriptions involving a flat (plano), concave, or opaque lens wouldn’t support proper light transmission or the necessary optical refraction. Therefore, the best description is transparent, bi-convex.