Characteristics of Lenses. Lens. Is a transparent object with at least one curved side that causes light to refract. Have 2 sides Either side could be plane, concave or convex.
Converging lenses have one or two convex surfaces and are thicker in the centre than on the edges.
Diverging lenses have one or two concave surfaces and are thicker at the edges than at the centre.
1 = 1 + 1
f di do
m = hi = -di