What is chromatic aberration in optics?

Chromatic aberration occurs when different wavelengths of light are refracted by varying amounts as they pass through a lens. This results in colors not focusing at the same point, leading to a distortion where colors appear to blur, particularly around the edges of an image.

The reason why option C is the correct answer lies in its description of this blurring effect. Because lenses typically have different refractive indices for different colors (or wavelengths) of light, the result is that colors can spread out and not focus precisely at the same spot. This is particularly noticeable in high-contrast images and can create a fringe effect that compromises image quality.

Understanding chromatic aberration is important as it helps in the design of lenses and optical systems to minimize this distortion, by using special coatings or lens materials that correct for these discrepancies in color focus.