photo-, phot-, -photic

(Greek: light; ultraviolet and infrared radiation; radiant energy)

photaugiaphobia, photaugiophobia (s) (noun) (no plural)
1. A pathological fear of light being directed upon the eyes: Whenever George had to go to the ophthalmologist for a regular checkup, he had photaugiaphobia because of his hatred of the glaring beam of luminance that was directed into his organs of vision.
2. An intolerance of light glare: Some plants, having photaugiaphobia, only grow in shady areas and avoid the sun, as with some forms of the fern, otherwise they would die.

Susan, affected by photaugiophobia, had to be very careful of the blazing sun in the desert which could cause photalgia, a pain caused by such dazzling rays of sunshine, so she always wore sunglasses as much as possible.

photesthesia (s) (noun), photesthesias (pl)
Sensitivity to light: Dr. Noel, the ophthalmologist, tested for photesthesia before prescribing new glasses for Hayden's aunt.
photesthesis (s) (noun) (no plural form)
Sensitivity to light: Because of her acute photesthesis, Laural always wore transition lenses when she went outside in the sunlight.
photic
1. Relating to light, especially when produced by living organisms.
2. In ecology, relating to or used to describe the area of the ocean where light penetrates and photosynthesis occurs.
photism
1. A synesthesia in which a sensation of color or light is associated with a sensation of hearing, taste, smell, or touch.
2. A visual sensation of color evoked by, or associated with, an auditory, olfactory, gustatory, or tactile stimulus.
photo (s), photos (pl)
1. As a noun, an informal term for photograph.
2. As a verb, to photograph or to take photographs.

A photo is a representation of a person or scene in the form of a print or transparent slide; recorded by a camera on light-sensitive material.

photo perception (s) (noun), photo perceptions (pl)
The ability to recognize or to know about light.
photoactinic
Giving off both luminous and actinic rays.
photoactive
Reacting chemically to sunlight or ultraviolet radiation.
photoaging
Premature aging of the skin due to long-term exposure to ultraviolet irradiation such as in sunlight.
photoagulator
A laser device that projects an intense beam of light into the interior of the eye and generates heat that coagulates vessels; such as, in the treatment of a detached retina.
photoallergen
An agent that elicits an allergic response to light.
photoallergic
Caused by or relating to an allergic sensitivity to light.
photoallergy, photoallergic
A delayed immunologic type of photosensitivity involving a chemical substance to which the individual has become previously sensitized.
photoautotroph, photoautotrophy
1. An organism that derives its energy exclusively from light and uses it to synthesize food.
2. Requiring only inorganic compounds for growth with carbon dioxide as the sole source of carbon (autotrophic) and deriving energy from photosynthesis; said of algae and certain photosynthetic bacteria.

Etymologically related "light, shine, glow" word families: ethero-; fulg-; luco-; lumen-, lum-; luna, luni-; lustr-; phengo-; pheno-; phospho-; scinti-, scintill-; splendo-.