Some ray diagrams may also show a third ray. Peep holes contain concave lenses. They are set into doors so the occupant can identify a visitor before opening the door.

Concave Convex Mirror has been created for the Alt Material exhibition, part of NGV's Melbourne Design Week 2020. The framework of Concave Convex Mirror is made of mild steel spun over a custom ...

Convex and concave lenses can both be used to correct defects of vision. The most commonly occurring defects of vision are ‘short sightedness’ and ‘long sightedness’. People who are ...