Optical aberration
Videos
In optics, aberration is a property of optical systems, such as lenses and mirrors, that causes the image created by the optical system to not be a faithful reproduction of the object being observed.
Image plane of a flat-top beam under the effect of the first 21 Zernike polynomials
Effect of Zernike aberrations in Log scale. The intensity minima are visible.
Laser guide stars assist in the elimination of atmospheric distortion.