optics (redirected from Geometrical optics)

optics /op·tics/ (op´tiks) the science of light and vision.

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op·tics (ptks)

n.

The science concerned with the properties of light, its refraction and absorption, and the refracting media of the eye.

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optics

[op′tiks]

Etymology: Gk, optikos, sight

1 (in physics) a field of study that deals with the electromagnetic radiation of wavelengths shorter than radio waves but longer than x-rays.

2 (in physiology) a field of study that deals with vision and the process by which the functions of the eye and the brain are integrated in the perception of shapes, patterns, movements, spatial relationships, and color.

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optics,

n the science concerned with the properties of light, its refraction and absorption, and the properties of the media of the eye that refract and absorb light.

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optics

the science of light and vision.

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optics 

1. The branch of physics which deals with the phenomena of light.

2. The elements and/or design of an optical instrument, including the eye (optics of the eye). See gaussian theory; Newton's theory; quantum theory; wave theory.
dispensing optics See ophthalmic optics.
dispensing optics See ophthalmic optics.
fibre optics A fine flexible glass or plastic rod that transmits light longitudinally by repeated total internal reflection. By using a bundle of such fibres in a fixed array, a complete image can be transmitted. As total internal reflection can occur even if the fibres are curved, the system is of great value for viewing or photographing inaccessible objects, such as internal organs of the body. Syn. fibre optic (although strictly this term is an adjective, e.g. a fibre optic cable, whereas the term fibre optics is a noun). See critical angle; endoscope.
first-order optics See paraxial optics.
gaussian optics See paraxial optics.
geometrical optics The branch of optics that deals with the tracing of light rays through optical systems. See sign convention; gaussian theory.
mechanical optics See ophthalmic optics.
ophthalmic optics 1. The branch of optics which deals with the design, measurement, assembly and fitting of lenses, spectacles, contact lenses, as well as optical aids for low vision patients. Syn. dispensing optics; mechanical optics. 2. In the UK and the Republic of Ireland it is used as a synonym for optometry. See optical dispensing; optometry.
optics of the eye The eye considered as an optical system composed of several elements, the two aspherical surfaces of the cornea (total power about +42 D), the two aspherical surfaces of the lens (total power +21 D), the depth of the anterior chamber (a change of 1 mm in depth corresponds to a change of about 0.7 D in the total power of the eye) and the refractive indices of the various media (it is a gradient in the lens) and their role in the formation of a retinal image. The total power of the eye is about +60 D. Syn. dioptric system of the eye. See constants of the eye; Table P5.
paraxial optics A simplified representation of geometrical optics which deals only with paraxial rays and in which the law of refraction and the fundamental paraxial equation are applicable. Syn. first-order optics; gaussian optics. See Lagrange's law; law of refraction; fundamental paraxial equation; paraxial ray.
physical optics The branch of optics that deals with the nature of light and with the phenomena of diffraction, interference, polarization and velocity of light. See quantum theory; wave theory.
physiological optics The branch of optics concerned with physiological, psychological and optical aspects of visual perception.
visual optics Branch of optics and optometry which deals with the dioptric system of the eye and its correction. See optics of the eye.

Table O2 Common optical symbols
f, f′	primary and secondary focal lengths
h, h′	object and image sizes
i, i′	angles of incidence or reflection and refraction
k, k′	distances from the corneal pole to the far point and to the retina, respectively
l, l′	distances of object and image from the optical system
n, n′	refractive indices of object and image space
u, u′ or w, w′ or α, α′	angular size of object and image
x, x′	distances between object and first focal point, and image and second focal point, respectively
r	radius of curvature
c	centre of curvature
A	ocular accommodation
As	spectacle accommodation
Amp	amplitude of accommodation
Add	addition for near vision
B	dioptric distance to near point of accommodation, measured from the eye
D	dioptre
d	vertex distance
d or dec	decentration
F	power
Fc	power of a contact lens correction
Fe	equivalent power; power of the eye
Fsp	power of a spectacle lens correction
Fv, Fv′	front and back vertex power
K	ocular correction
K′	vergence of the retina or dioptric length of the eye
E, E′	centres of entrance and exit pupils
L, L′	object and image vergences
M or m	magnification
F, F′	first and second focal points
N, N′	first and second nodal points
P, P′	first and second principal points
RSM	relative spectacle magnification
SM	spectacle magnification
ε or P	refractive power of a prism
Χ	prism dioptre