Which type of lens primarily causes Chromatic Aberration?

Chromatic aberration primarily occurs in convex lenses. This phenomenon is a result of the lens's ability to bend light rays to form an image. Convex lenses are thicker in the center than at the edges, and they converge rays of light to a focal point. However, different wavelengths (or colors) of light are refracted by varying degrees when passing through a convex lens.

Because each color has a different wavelength, they are focused at different points along the optical axis of the lens. This causes a situation where, instead of producing a sharp image for all colors, the image displays as a series of colored fringes or blurs—essentially, the lens fails to bring all colors into a single sharp focus. Convex lenses are often used in optical devices like cameras, telescopes, and glasses for correcting hyperopia, where this aberration can affect the quality of the images produced.

In contrast, concave lenses, cylindrical lenses, and flat lenses do not primarily exhibit chromatic aberration in the same way convex lenses do. Concave lenses diverge light rays and typically don't focus light to a central point; cylindrical lenses focus light into a line and are more prone to other types of aberrations; flat lenses (which have no curvature