9. Glossary

agrandissement; enlargement

Ratio between the transverse size of the image and the transverse size of the object, also called "magnification"; it is always transverse in this article.

aberrations chromatiques; chromatic aberration

Optical defect caused by the fact that the optical index varies with wavelength. For example, the focal point of a beam passing through a lens is not at the same position depending on the wavelength used.

accommodation; accommodation

Adaptation by the eye of its vision, whether near or far, by modifying the vergence of its crystalline lens with the help of ciliary muscles. For these muscles, and therefore the eye, to be at rest, the beam of light entering the eye must be parallel, so that the image of an object is formed directly on the...