| photophthalmia | Keratoconjunctivitis caused by ultraviolet energy, as in snow blindness, exposure to an ultraviolet lamp, arc welding, or the short circuit of a high-tension electric current. See: photoretinopathy. Origin: photo-+ G. Ophthalmos, eye (05 Mar 2000) |
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| photopia | Synonym: photopic vision. Origin: photo-+ G. Opsis, vision (05 Mar 2000) |
| photopic | Pertaining to photopic vision. (05 Mar 2000) |
| photopic adaptation | The visual adjustment occurring under increased illumination in which the retinal sensitivity to light is reduced. See: light-adapted eye. Synonym: photopic adaptation. (05 Mar 2000) |
| photopic eye | An eye that has been exposed to light, with bleaching of rhodopsin (visual purple) and insensitivity to low illumination. Synonym: photopic eye. (05 Mar 2000) |
| photopic vision | Vision when the eye is light-adapted. See: light adaptation, light-adapted eye. Synonym: cone vision, photopia. (05 Mar 2000) |
| photopigment | <plant biology> Pigment involved in photosynthesis in plants. Includes chlorophyll, carotenoids and phycobilins. (31 Dec 1997) |
| photoplethysmography | Plethysmographic determination in which the intensity of light reflected from the skin surface and the red cells below is measured to determine the blood volume of the respective area. There are two types, transmission and reflectance. (12 Dec 1998) |
| photopsia | <medicine> An affection of the eye, in which the patient perceives luminous rays, flashes, coruscations, etc. See phosphene. Origin: Gr. Opsis = vision (09 Mar 1998) |
| photopsin | The protein moiety (opsin) of the pigment (iodopsin) in the cones of the retina. (05 Mar 2000) |
| photopsy | <medicine> An affection of the eye, in which the patient perceives luminous rays, flashes, coruscations, etc. See phosphene. Origin: Gr. Opsis = vision (09 Mar 1998) |
| photoptarmosis | Reflex sneezing that occurs when bright light stimulates the retina. Origin: photo-+ G. Ptarmos, a sneezing, + -osis, condition (05 Mar 2000) |
| photoradiation | Treatment of cancer by intravenous injection of a photosensitizing agent, such as haematoporphyrin, followed by exposure to visible light of superficial tumours or of deep tumours by a fibreoptic probe. Synonym: photochemotherapy, photoradiation therapy. (05 Mar 2000) |
| photoradiation therapy | Treatment of cancer by intravenous injection of a photosensitizing agent, such as haematoporphyrin, followed by exposure to visible light of superficial tumours or of deep tumours by a fibreoptic probe. Synonym: photochemotherapy, photoradiation therapy. (05 Mar 2000) |
| photoreaction | A reaction caused or affected by light; e.g., a photochemical reaction, photolysis, photosynthesis, phototropism, thymine dimer formation. (05 Mar 2000) |