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1. Of or relating to light.
2. Penetrated by or receiving light.
3. Designating or relating to the layer of a body of water that is penetrated by sufficient sunlight for photosynthesis: the photic zone of the ocean.


1. (General Physics) of or concerned with light
2. (Biology) biology of or relating to the production of light by organisms
3. (Biology) Also: photobathic designating the zone of the sea where photosynthesis takes place
[C19: from photo- + -ic]


(ˈfoʊ tɪk)

1. of or pertaining to light.
2. pertaining to the generation of light by organisms, or their excitation by means of light.
3. pertaining to the upper zone of a body of water, delineated by the depth to which sufficient sunlight penetrates to support photosynthesis.
[1835–45; < Greek phōt- (see phot) + -ic]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.photic - of or relating to or caused by light
References in periodicals archive ?
Seven study participants with a PPR to intermittent photic stimulation at baseline were randomized to single doses of CVL-865 (17.5 or 52.5 mg), lorazepam 2 mg (a commonly prescribed benzodiazepine used as an active control), or placebo.
The cyclocrinitids were most common at relatively shallow depths, below the wave base but within the photic zone.
One in three people are Photic, meaning they sneeze with bright light, an inherited trait.
Algae photosynthesize in the photic zone at the surface, forming the base of the food chain.
Cortical response of the anaesthesized cat to gross photic and electrical afferent stimulation.
Time was taken to explain the possibilities of photic phenomena (Glare, haloes) and whether the patient would accept it as a trade-off for spectacle independence.
As these plumes often reach up into the productive photic zone, they discharge large quantities of material into the surface water layers.
In youth, the vitreous is completely clear and transparent, allowing light to pass freely to the back of the eyeball, where the retina collects photic energy and turns it into nerve impulses that the brain reconstructs into images.
Temporal dynamics of late-night photic stimulation of the human circadian timing system.
In addition, preliminary data indicate they also differ in the photic sensibility threshold which produces inhibition of their movements of reaction (unpublished data).
Clinical studies using multimodal imaging including optical coherence tomography (OCT) and fundus autofluorescence imaging (FAF) have reported finding changes of the photoreceptor cells and retinal pigment epithelium during the acute phase and an increased choroidal thickness due to photic injury during the chronic phase [3-5].
A photic driving response was confirmed, i.e., presence of 40 Hz oscillations in frontal and occipital leads (Supplementary Figure 1B).