- Not to be confused with barrel distortion, in which the image appears to be warped onto a sphere.
Spherical aberration is an optical effect observed in an
optical device (
lens,
mirror, etc.) that occurs due to the increased
refraction of light rays when they strike a lens or a
reflection of light rays when they strike a mirror near its edge, in comparison with those that strike nearer the centre. It signifies a deviation of the device from the norm, i.e., it results in an imperfection of the produced image.