Light adaptation Health Dictionary

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Light Adaptation: From 1 Different Sources

reflex changes in the eye to enable vision either in normal light after being in darkness or in very bright light after being in normal light. The pupil contracts (see pupillary reflex) and the pigment in the *rods is bleached. Compare dark adaptation.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Adaptation

A slowly diminishing reaction of a sense organ to persistent or repetitive stimulation. For example, a persistent smell may after a while result in the nose failing to signal its presence; the pressure-sensitive nerve endings in the skin may become accustomed to the presence of clothes on the body; regular background noise may be screened out by the cochlear nerve that links ear and brain.... adaptation

Adaptation (of Residence)

Permanent fixtures or alterations to a home to help someone get about or manage better (distinguished from ‘aids’ or ‘equipment’, which are more portable).... adaptation (of residence)

Home Adaptation

See “adaptation”.... home adaptation

Light

(American) A lighthearted woman Lite, Lyte... light

Light Reflex

Pupillary constriction in the EYE in response to light. The direct light re?ex involves pupillary constriction in the eye into which a light is shone; the consensual light re?ex is the pupillary constriction that occurs in the other eye. The a?erent or inward pathway of the re?ex is via the optic nerve, and the e?erent or outward pathway is via the occulomotor nerve.... light reflex

Light Traps

A mechanical trap which use a combination of light and/or carbon dioxide to attract and trap adult mosquitoes, e.g. Centres for Disease Control and Prevention (CDC) Light Trap.... light traps

Ultraviolet Light

Invisible light from the part of the electromagnetic spectrum immediately beyond the violet end of the visible light spectrum. Long wavelength ultraviolet light is termed , intermediate , and short.

Ultraviolet light occurs in sunlight, but much of it is absorbed by the ozone layer. The ultraviolet light (mainly ) that reaches the earth’s surface causes the tanning effects of sunlight and the production of vitamin D in the skin. It can have harmful effects, such as skin cancer (see sunlight, adverse effects of).

Ultraviolet light is sometimes used in phototherapy.

A mercury-vapour lamp (Wood’s light) can also produce ultraviolet light.

This is used to diagnose skin conditions such as tinea because it causes the infected area to fluoresce.... ultraviolet light

Dark Adaptation

the changes that take place in the retina and pupil of the eye enabling vision in very dim light. Dark adaptation involves activation of the *rods – the cells of the retina that function best in dim light – and the reflex enlargement of the pupil (see pupillary reflex). Compare light adaptation.... dark adaptation

Light Reflex

see pupillary reflex.... light reflex

Polymorphous Light Eruption

see photodermatosis.... polymorphous light eruption

Wood’s Light

ultraviolet light filtered through a nickel oxide prism, which causes fluorescence in skin and hair affected by some fungal and bacterial infections and is therefore useful in diagnosis. For example, *erythrasma fluoresces coral pink, while scalp ringworm caused by Microsporum species fluoresces green. [R. W. Wood (1868–1955), US physician]... wood’s light

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