A condition caused by undue exposure to sunlight. It is characterized by reduced retinal sensitivity to light.

1. A description of those parts of the ocean that are not reached by sunlight, or plants that grow there without photosynthesizing.
2. A reference to any environement or habitat that has no sunlight of biological significant intensity.
3. Literally, “no light”.

The absence of any directed response to a light stimulus in a motile organism; negative phototaxis.

1. An orientation response away from light; negative phototropism.
2. The absence of an orientation response to light.

An orientation response of an organism or structure at right angles to the direction of incident light.

Orientation at a right angle to the direction of incident light.

The zone of intermediate light inensity in a body of water, with insufficient light for photosynthesis but sufficient light for behavioral responses.

1. The surface zone in a sea or large lake that has sufficient light penetration for net photosynthesis to occur.
2. A reference to the upper layer of a body of water that allows the penetration of enough light to support photosynthetic, or green plants.

Orientation response of plant structures to maximize incident illumination; euphototropic.

Tolerant of a wide range of light intensity.

A unit of illumination in the centimeter-gram-second system equal to one lumen per square centimeter.

Ocular pain caused by light; photodynia.

An allotropic change with color alteration due to light, as the change of yellow into red phosphorus. Allotropism is the existence of a substance in two or more distinct forms with distinct physical properties, e.g., graphite and diamond, allotropic forms of carbon.

1. A pathological fear of light being directed upon the eyes.
2. An abnormal intolerance of light glare.

Sensitivity to light.

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.

A synesthesia in which a sensation of color or light is associated with a sensation of hearing, taste, smell, or touch.

Giving off both luminous and actinic rays.

Reacting chemically to sunlight or ultraviolet radiation.

Premature aging of the skin due to long-term exposure to ultraviolet irradiation such as in sunlight.

An agent that elicits an allergic response to light.

Caused by or relating to an allergic sensitivity to light.

A delayed immunologic type of photosensitivity involving a chemical substance to which the individual has become previously sensitized.

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.

Bacteria that derive energy from light by the process of photosynthesis.

That department of biology that dealsnstrument designed to destroy tissues with a concentrated light beam, such as a laser.BR>

1. In biology, dependent upon light for existence.
2. Used to describe organisms that need light in order to live and grow.

1. The promotion or stimulation of a reaction by light.
2. The acceleration or deceleration of the speed at which a chemical reaction occurs, caused by electromagnetic radiation and especially visible light.

A substance which in sunlight is utilized; such as, chlorophyll in the photosynthesis of carbohydrates by green plants.

Promoted or stimulated by light; pertaining to, characterized by, or causing photocatalysis.

A procedure in which tissue is destroyed by using a light beam such as a laser.

A surgical ilnstrument designed to destroy tissues with a concentrated light beam, such as a laser.

A cell capable of perceiving the presence of light.

Pertaining to the chemical properties of light; chemically reactive in the presence of light or other radiation.

The branch of chemistry having to do with the effect of light or other radiant energy while producing chemical action, as with photographs.

Treatment by means of drugs that react to ultraviolet radiation or sunlight.

Of or pertaining to the chromatic or coloring action of light; pertaining to or produced by photochromy.

A reference to a material, such as certain glass or film, which turns dark when exposed to light and returns to its normal trasparency with the removal of the light source.

A microorganism whose pigmentation develops as a result of exposure to light.

Moving in response to the stimulus of light.

1. Condensation of protein material by the controlled use of an intense beam of light; used especially in the treatment of retinal detachment and the destruction of abnormal retinal vessels, or of intraocular tumor masses.
2. A technique using intense light energy, as from a laser, to produce scar tissue used in treating certain eye disorders, in medical and biological research, etc.

The breakdown of a chemical compound into simpler substances by means of incident electromagnetic energy, especially visible light.

A copy of something printed, written, or drawn that is produced almost instantly by a photographic process in a machine designed for this purpose.

Pertaining to a dermatitis in which exposure to light is an important factor.

Specialized bioluminescent cells containing lumisomes, as in the sea pansy.

Able to be decomposed into a simpler substance through prolonged exposure to incident electromagnetic energy, especially ultraviolet light.

An abnormal state of the skin in which light is an important factor. Inflammation of the skin caused by light; especially, sunlight.

A morbid condition produced in the skin by exposure to light.

1. Of or relating to the energy or force exerted by light.
2. Powerful in the light; used particularly for the action exerted by fluorescent substances in the light.

1. A branch of biology dealing with the effects of light on living organisms.
2. The activating effect of light on living organisms, as in causing phototropism in plants.
3. The study of the vitalizing effect of light.

An intolerance to light; photophobia.

1. Pain caused by intense light.
2. Ocular pain caused by light; photalgia.

Intolerance of light; photophobia.

Pertaining to the electric effects of light or other radiation.

An electron emitted from a metallic surface when the latter is illuminated with light, especially with light of short wavelength.

The process of making a printing plate by photographing an image onto a metal plate and then etching the image.

Erythema (redness of the skin) due to exposure to light.