Why does a light ray passes undeviated from the optical centre of a lens??
Answers
Your question:
Why does a light ray passes undeviated from the optical center of a lens?
Answer: The center of a lens is comparatively flat that the other points of the lens.
This can be found in thin lens rather than thick lenses. Because, it doesn’t mean that there is no refraction when we mean there is no deviation in the ray that is passed through. In the case of thin lenses; there will be refraction but it is negligible or not that much worth for consideration. So we can refer the ray that passes through the center of the lens as just a straight line.
When we say that there is no deviation, we only mean that the incident ray and the emergent ray are parallel to each other. For thin lenses, the refraction inside the lens is negligible and therefore we represent the ray passing through the optic centre as a straight line.