What is the term for the light rays passing through the edges of a lens being refracted more than those passing through the center?

• A. Chromatic Aberration
• B. Spherical Aberration
• C. Coma
• D. Astigmatism

Answer: (B)

The correct answer is related to the phenomenon known as spherical aberration. This occurs when light rays that pass through the edges of a lens are refracted more than those that pass through the center. Due to the shape of a spherical lens, rays entering at different angles experience varying degrees of refraction, causing less than ideal focusing of light. This results in images that may appear blurred or not sharply defined at the edges.

In understanding the context of the other terms: chromatic aberration refers to the dispersion of light into different colors, which is not specifically about the refraction at the edges versus the center of a lens. Coma describes a specific aberration resulting in images that appear comet-like, often affecting point sources of light. Astigmatism is typically a term used in the context of the eye or lens systems that cause different focal points in different meridians, rather than the edge versus center refraction of a lens. Thus, spherical aberration is the precise term for the effect described in the question.