What machine did Leonardo da Vinci design to grind concave and convex mirrors?

Leonardo da Vinci designed a mirror-grinding machine for shaping concave and convex mirrors.

The machine belongs to his investigations of optics and mechanical production. Grinding and polishing a curved mirror requires controlled motion and a surface of carefully maintained shape; Leonardo’s design attempted to mechanize that work rather than relying entirely on hand movements.

Leonardo was especially interested in reflection, light, vision, and the geometry of curved surfaces. His optical studies were connected with his fascination with the eye and with attempts to understand how images are formed.

This device is not the same as a modern telescope or camera. Leonardo designed machines and studied optical principles, but the existence of a successful production workshop based on this particular machine is not established by surviving evidence.