what is mean by spherical lens
Answers
Answer:
A "spherical lens" is a lens whose surface has the shape of the surface of a sphere. On this page, we will determine some values for the focal length of a spherical lens.
A spherical lens doesn't actually bring parallel rays to a common focus (see figure 1). Rather, the "focus" of the lens depends on the distance from the distance from the center of the lens, with light passing through the edges of the lens coming to a focus closer to the lens than light passing through the center. This produces the phenomenon of "focus shift", which is well known to photographers: If your lens suffers from severe "focus shift", and you focus the image with the diaphragm wide open, and then stop down to take the picture, the picture won't be in focus. With the lens opened wide the image is dominated by light passing through the lens far from the center; consequently, it's the edge rays which you've adjusted the lens to bring to a sharp focus. The center rays, on the other hand, are coming to a focus behind the film plane; when the lens is stopped down, only those (out of focus) center rays are left.
Answer:
spherical lens are of two types concave and convex the are used for magnifying and doctors use these lens to see big image of teeth