dark adaptation


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dark adaptation

n.
The physical and chemical adjustments of the eye, including dilation of the pupil and increased activity of rods in the retina, that make vision possible in relative darkness.

dark′-a·dapt′ v.
dark′-a·dapt′ed (-ə-dăp′tĭd) adj.

dark′ adapta`tion


n.
the reflex adjustment of the eye to dim light or darkness, consisting of a dilation of the pupil, an increase in the number of functioning rods, and a decrease in the number of functioning cones.
[1905–10]
dark′-a•dapt`ed, adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.dark adaptation - the process of adjusting the eyes to low levels of illumination; cones adapt first; rods continue to adapt for up to four hours
adaptation - (physiology) the responsive adjustment of a sense organ (as the eye) to varying conditions (as of light)
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Retinal vessel dilation occurs in response to experimental hypoxia and flicker stimulation [11-13], and lower glycemia suppresses retinal electroretinographic signaling and dark adaptation. Hence, there is a reason to suspect that hypoglycemia may dilate retinal vessels [14-17].
This reflex can appear either homogeneous or in streaks in the fundus and disappears after prolonged dark adaptation"1,2.
Dynamically tunable solid-state lighting technology is also ideal for mitigating issues associated with dark adaptation. Typically, healthcare rooms are unfamiliar to patients with nighttime visual barriers, making room navigation difficult under lowlight conditions.
The point on the dark adaptation curve when the sensitivity of the rods initially exceeds that of the cones is known as the rod-cone break.
But the most important part of dark adaptation involves chemical changes in your retina, and these require many minutes.
In vivo, retinal damage in mice was induced by exposure to white light at 8000Ix for 3h after dark adaptation. Photoreceptor damage was evaluated by measuring the outer nuclear layer thickness at 5days after light exposure and recording the electroretinogram (ERG).
It's quite an entrance and easy to understand why Rupert Sanders, the director of her latest film, a dark adaptation of the Snow White fairytale, chose her as his wicked but beautiful Queen Ravenna.
Affected individuals first experience defective dark adaptation or nyctalopia (night blindness), followed by reduction of the peripheral visual field (known as tunnel vision) and, sometimes, loss of central vision late in the course of the disease.
All the tricks of deep sky observing at the limit will be necessary, such as full dark adaptation, averted vision and a pristine dark sky site, along with a telescope in the half-metre class.
The dark adaptation sees the detective stranded on board the train while it is caught in a snowdrift in Eastern Europe.
The ERGs were recorded from the surface of the crystalline cones of the compound eyes after at least 30 min of dark adaptation. The response was an "on" negative potential consisting of an initial phasic component followed by a maintained or plateau component that lasted for the duration of the illumination.
A FAST-paced, deliciously dark adaptation of The Strange Case of Dr Jekyll & Mr Hyde is at Wrexham's Glyndwer University this month.