photo-, phot-, -photic

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

photosensitive (adjective), more photosensitive, most photosensitive
1. Reacting to incident electromagnetic radiation, especially visible, infrared, and ultraviolet light: Huston used photosensitive paper for his experiments which involved exposing plants to various kinds of radiation during his studies in botany.
2. Concerning an abnormally heightened reactivity to sunlight: Some of the plants in the sun room were photosensitive to the sunshine that poured through the windows in the morning.
photosensitivity (s) (noun), photosensitivities (pl)
An abnormal skin reaction to sunlight: Photosensitivity usually results as a skin rash that appears in response to light coming in contact with the skin and it can be caused by substances that have been eaten or something that has been applied to the skin.
photosensitization (s) (noun), photosensitizations (pl)
A condition in which the skin reacts abnormally to light, especially ultraviolet radiations or sunlight: Photosensitization can be caused by the presence of drugs, hormones, or certain diseases, such as lupus, a chronic inflammatory ailment.
photosensitize (verb), photosensitizes; photosensitized; photosensitizing
To provide a strong physical reaction to the influence of light, such as an organism, a cell, or skin: Because he wanted a tan, Pedro used a special cream on his arms to photosensitize them.
photosensor oculography (s) (noun), photosensor oculographies (pl)
The process by which the position and movement of the eye is measured by the use of a light sensitive device: Ingrid's doctor had a specialist examine her eyes using a photosensor oculography procedure in order to make a better diagnosis of what was causing her to lose her vision.
1. The outermost visible layer, or surface, of the sun.

The layer of the sun that corresponds to the solar surface viewed in white light or the region from which light escapes from the sun into space.

2. The intensely bright gaseous outer layer of a star, especially the sun.

Sunspots and faculae are both features of the photosphere. The faculae are groups of small shining spots on the surface of the sun which are brighter than the other parts of the photosphere.

A device for monitoring the fetal heartbeat (of an unborn baby) that emits a flash of light at each beat.
1. The biological synthesis of chemical compounds in the presence of light.
2. The production of organic substances, primarily sugars, from carbon dioxide and water which occur in green plant cells.
3. The fundamental chemical process in which green plants (and certain other organisms) utilize the energy of sunlight or other light to convert carbon dioxide and water into organic chemical energy.

Photosynthesis is often described as the most important chemical reaction on earth and is found in bacteria, cyanobactria, algae, and most plants.

The coupling of light energy to chemical energy is, directly or indirectly, the basis for nearly all life on earth.

"From sea slugs to salamanders, many animals can naturally tap into solar power"

There are plenty of free-living photosynthetic animals; including photosynthetic flatworms up to 15 millimetres long that can be found in huge numbers in places.

Then there are the jellyfish-like Vellela, which float on the sea surface, and the upside-down jellyfish. Most striking of all are the many different kinds of solar-powered sea slugs.

—Quote from "Light diet: Animals that eat sunshine"
by Debora MacKenzie and Michael Le Page;
New Scientist; December 13, 2010; pages 32-35;
Relating to, or taking part, in a process of photosynthesis.
photosynthetic efficiency, photovoltaic conversion efficiency
The percentage of the total available light captured by plants that is subsequently converted into chemical energy.
phototachometer, phototachometric, phototachometrical
An apparatus for determining the velocity of light.
The measurement of the velocity of light.
Of, pertaining to, or exhibiting phototaxis.
phototaxis, phototaxy
1. The movement of an organism in response to color or light pattern stimulus.
2. Taxis of an organism elicited in response to the source of a light stimulus.
3. In botany, the movement of a part of a plant toward or away from light sources.
1. The treatment of disease, e.g., herpes simplex, psoriasis, neonatal hyperbilirubinemia, or seasonal affective disorder, by exposure to light; especially, by variously concentrated light rays of specific wavelengths.
2. The use of ultraviolet radiation in the treatment of skin deseases.

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