photo-, phot-, -photic

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

An instrument used in map production for producing printed names photographically.
photo-oxidation, photooxidation
A process of oxidation driven by radiant energy (light).
photoparesthesia (s) (noun), photoparesthesias (pl)
An abnormal sensation caused by exposure to light: Nancy developed photoparesthesia on her left arm which was exposed to a lot of sunlight because she often had to drive with the car window down due to the fact that her air conditioner was not functioning.
photopathologic (adjective), more photopathologic, most photopathologic
Pertaining to any abnormality resulting from excessive exposure to light: When Jenny was at the opthalmologist's, Dr. Lite told her to wear sunglasses when out during the day, and even wear a hat to keep the sunlight out of her eyes in order to avoid any irreversible photopathologic ailment.
photopathy (s) (noun), photopathies (pl)
1. A pathological effect caused by light: A form of photopathy can occur when a person hikes in a region of glaciers on a sunny day and doesn't wear any sunglasses!
2. The influence of light upon organisms: Photopathy can relate to life forms that migrate from an area of greater light (positive photopathy) to one with less intensity of light (negative photopathy).
3. Any abnormal change in the skin induced by light: When Bob was out doing gardening, he always wore a shirt or jacket with long sleeves in order to protect his arms from any photopathies that might affect his skin.
1. The length of a day.
2. The amount of time that an organism is exposed to daylight.
1. A property of living organisms wherein biochemical, physiological, and behavioral changes occur in response to systematic variations in light and darkness, as with the seasons or day and night.
2. Any of various behavioral and physiological changes in an organism in response to the amount of daylight to which the organism is exposed; for example, the relative length of day and night on a seasonal or daily basis.
The study of the effects of light and other radiations on drugs and on their pharmacological action.
photopheresis (s) (noun) (no plural)
A process in which peripheral blood is exposed in an extracorporeal flow system to photoactivated 8-methoxypsoralen (methoxsalen) and ultraviolet light; a procedure known as puva therapy.

Photopheresis is at present a standard therapy for advanced cutaneous T-cell lymphoma. It shows promise in the treatment of autoimmune diseases.

photophile (s) (noun), photophiles (pl)
A form of life that grows of a life form where there is abundant light: Some plants that are photophiles are the moss rose, the zinnia and the marigold, all of which love lots of sunlight!
photophilia (s) (noun) (no pl)
A partiality to grow in bright sunlight: In the article on photophilia, Vanessa read that certain plants, like the sunflower or zinnia, thrive best where there is lots of sunshine the whole day.
photophobia (s) (noun), photophobias (pl)
1. An excessive avoidance of light: Mrs. Jones, suffering from photophobia, had light-coloured eyes which were very sensitive to the brilliance of the sun and caused her much discomfort and pain.
2. In botany, the tendency to thrive in reduced light: Moss, which exhibits photophobia, grows in moist, shady areas and won't survive well in sunlight!
3. Intolerance of full light: Photophobia is indicated by troglobites, animals which spend their entire lives in caves and having adapted a loss of body pigmentation, a loss of sight, and slow metabolic activity.
A man is afraid of light and wears sunglasses even inside his house.
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photophobotaxis (s) (noun) (no plural)
In biology, a response of an organism to a temporal change in light intensity:

Photophobotaxis can be explained by a cell or living thing moving towards the intensity of brilliance, termed as positive, or moves away from the source, termed as negative.

An instrument for producing sound by the action of light waves.
photophore (s), photophores (pl)
1. A luminous light organ on many deep sea and some nocturnal fish, squids, and shrimps.
2. The light-producing organs found especially in marine fishes which produce light from specialized structures or that derive light from symbiotic luminescent bacteria.

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