Bioconcave is when both surfaces are concave.

Bioconcave is when both surfaces are concave.

• A. Bioconvex
• B. Plano convex
• C. Bioconcave
• D. Meniscus

Answer: (C)

Bioconcave means two inward-curving surfaces. The prefix bi- indicates two surfaces, and concave describes inward curvature. With both sides curved inward, the lens is thinner at the center on both faces and diverges light rays, giving a negative focal length. This distinguishes it from other shapes: bioconvex has two outward-curving surfaces and converges light; plano-convex has one flat and one curved surface; a meniscus has one concave and one convex surface and can diverge or converge depending on the curvature balance. So the description matches the term correctly.

Bioconcave means two inward-curving surfaces. The prefix bi- indicates two surfaces, and concave describes inward curvature. With both sides curved inward, the lens is thinner at the center on both faces and diverges light rays, giving a negative focal length. This distinguishes it from other shapes: bioconvex has two outward-curving surfaces and converges light; plano-convex has one flat and one curved surface; a meniscus has one concave and one convex surface and can diverge or converge depending on the curvature balance. So the description matches the term correctly.