What is "stigmatism"

1660s, "a branding," from Greek stigmatizein, from stigmat-, stem of stigma (see stigma). Meaning "condition of being affected with stigmata" is from 1897.

n. 1 (context optics English) Image-formation property of an optical system which focuses a single point source in object space into a single point in image space 2 (context medicine English) Normal eyesight, anastigmatic state 3 (context pathology English) State of having stigma

1. n. the condition of having or being marked by stigmata

2. (optics) condition of an optical system (as a lens) in which light rays from a single point converge in a single focal point [ant: astigmatism]

3. normal eyesight

In geometric optics, stigmatism refers to the image-formation property of an optical system which focuses a single point source in object space into a single point in image space. Two such points are called a stigmatic pair of the optical system. Many optical systems, even those exhibiting optical aberrations including astigmatism, have at least one stigmatic pair. Stigmatism is applicable only in the approximation provided by geometric optics. In reality, image formation is at best diffraction limited and point-like images are not possible.