Question

Is the optical center always at the center of the lens?

Answer 1

Step1: Optical center

1. The primary axis is the line that runs through the center of the lens.
2. The optical center of the lens, shown by C in the diagram above, is the point where the major axis passes through the lens.
3. Consider the two rays A and B in the diagram. Ray A refracts and bends towards the primary axis after passing through the lens. After passing through the optical center, ray B becomes undeviated.
4. The optical center of the lens is the point in the middle of the lens where the incoming ray passes through without deviating.
5. The optical center will always be at the center if both the curved surfaces are symmetrical.

Hence, if both the curved surfaces are symmetrical, then the optical center will be at the center.