NCERT · Class 10 · Science · Light – Reflection and RefractionWhat is the optical center of a spherical lens?

The optical center of a spherical lens is a very special central point lying directly inside the lens on its principal axis, through which any ray of light passes without suffering any deviation or bending. Even though the ray may undergo lateral displacement if the lens is thick, a light ray passing straight through the optical center continues its path undeviated in direction. This point acts as the reference origin for measuring all kinds of distances associated with lenses under the Cartesian sign convention system.