light adaptation

The process for light adaptation occurs over a period of five minutes.

Using increment threshold experiments, light adaptation can be measured clinically.

Therefore, postnatal maturation of the retinal structures has led to strong light adaptations for infants.

With light adaptation, the eye has to quickly adapt to the background illumination to be able to distinguish objects in this background.

The state of adaptation of one eye can have a small effect on the state of light adaptation of the other.

The bleaching of rhodopsin and the narrowiviy of the pupil on re-emergence into full light is light adaptation.

Light adaptation characterized by a decrease in rod sensitivity in the presence of background illumination has been shown to be mediated by Ca 2+ (refs 26, 27).

Factors such as grazing, viral mortality, genetic variability, light adaptation, temperature as well as nutrients are certainly involved, but remain to be investigated on a rigorous and global scale.

Affected individuals may experience defective light to dark, dark to light adaptation or nyctalopia (night blindness), as the result of the degeneration of the peripheral visual field (known as tunnel vision).

Reduced Ca 2+ induced under conditions of light adaptation will result not only in an increase in cGMP, but also in a higher affinity of the channel for cGMP.

Then a reduction in sensitivity produced by light adaptation will, for a test colour that stimulates A alone, produce an intensity depression of R' but no colour change; similarly if B or C are stimulated alone."

On this basis, Ca 2+ may regulate photorecovery and light adaptation not only by regulating guanylate cyclase activity and phosphodiesterase activation, but also by modulating the affinity of the channel for cGMP.

To improve tunnel safety for motorists, and decrease the tunnel lighting requirements, the original tunnel entrance faces were sandblasted to remove white paint and repainted a less luminescent tan color to reduce the range of visual light adaptation required by drivers.

On the basis of these studies, Ca 2+ is suggested to play a central role in photorecovery and light adaptation, not only by regulating guanylate cyclase, possibly through recoverin, but also by modulating the cGMP-gated channel through calmodulin interaction with the 240K protein.