The point at which light rays parallel to the optical axis meet after reflection or refraction is the

• A. Optical Axis
• B. Real Image
• C. Focal Point
• D. Cornea

Answer: (C)

When light rays that travel parallel to the optical axis are bent by a lens or mirror, they converge at one point called the focal point. For a converging lens, parallel rays are refracted toward the axis and meet at the focal point on the opposite side of the lens. For a concave mirror, parallel rays reflect and come together at the focal point in front of the mirror. The optical axis is just the central line, and a real image is formed where rays actually meet. The cornea is a part of the eye, not the general meeting point of parallel rays. So the correct term for that meeting point is the focal point.