The convex lens is thicker in the middle and thinner at the edges. They are converging lenses. The concave mirror is thinner at the middle and thicker at the edges. They are diverging lenses.
So, Is the human eye concave or convex?. The human eye has a biconvex lens. The lens in the eye refracts the light and focuses it on the retina. Unlike the normal lens, the biconvex lens in the eye can change the shape. The shape of the lens changes to adjust the focal length of the eye, thus allowing the eye to focus clearly on the objects at varying distances. The ability of the lens to adjust from far to near focus is called accommodation.