Why would you see symmetry as being important, in a lens? How could you go about determining what would be the effect if the radii were not identical?I hope that they are same, otherwise there won't be symmetry.
Refraction through a thin lens refers to the bending of light as it passes through a lens. This bending is caused by a change in the speed of light as it travels from one medium to another.
A thin lens refracts light by causing the light rays to bend towards or away from the normal, depending on the shape and curvature of the lens. This bending is due to the change in the direction of the light as it enters and exits the lens.
Convex lenses are thicker in the middle and thinner at the edges, causing light rays to converge and meet at a focal point. Concave lenses are thinner in the middle and thicker at the edges, causing light rays to diverge.
The focal length of a lens is determined by the curvature of the lens and is the distance between the lens and the focal point. It is usually measured in meters or centimeters and is a key factor in determining the magnification of an image.
A real image is formed when light rays actually converge at a point to form an image, while a virtual image is formed when light rays only appear to converge at a point. Real images can be projected onto a screen, while virtual images cannot.