What is spherical aberration in lenses?

Spherical aberration is a lens defect that causes light rays to converge at different points.

Spherical aberration occurs when light rays passing through the edges of a lens are refracted differently than those passing through the centre. This results in a blurred image, as the different rays do not converge at the same point.

The effect of spherical aberration can be reduced by using a lens with a larger diameter, as this allows more of the light to pass through the centre of the lens. Alternatively, a lens with a flatter surface can be used, as this reduces the amount of refraction at the edges.

Another way to reduce spherical aberration is to use multiple lenses, such as in a compound lens system. By using lenses with different curvatures, the aberrations can be cancelled out, resulting in a clearer image.

Spherical aberration is an important consideration in the design of optical systems, particularly in applications such as microscopy and astronomy, where high levels of precision are required. By understanding the causes and effects of spherical aberration, physicists and engineers can develop more effective and efficient optical systems.