photo-, phot-, -photic +

Magnetism induced by the action of light.

1. An irresistible craving for light or the sun (heliolatry).
2. A morbid or exaggerated desire for light.
3. Maniacal symptoms increased by the effect of light.

1. An instrument used in measuring the intensity of light, especially in determining the relative intensity of light from different sources.
2. A device for measuring the intensity of infrared, ultraviolet, or visible light.
3. A device for testing the sensitivity of the eye to light by determining the light minimum.

1. The measurement of the visible portion of radiant energy (light).
2. Measuring the characteristics of visible radiation (light); such as, its luminous intensity or illuminance, relative to standard references.

A photograph taken through a microscope.

1. The art of obtaining photographs of microscopic objects on a magnified scale.
2. An enlarged photograph of an object viewed with a microscope, as distinguished from a microphotograph.

The regulation of a form by light, as in the induction of flowering in plants by a minimal period of daylight.

1. The quantum of electromagnetic radiation, which by definition, travels at the speed of light.
2. The quantum of the electromagnetic field that manifests itself by absorption or emission only in multiple quantum units of energy.
3. A unique massless particle that carries electromagnetic force.

One-sided growth due to the action of light.

The opening and closing of evening primrose flowers upon exposure to dark and light is one example.

The process of taking a succession of simultaneous photographs of a cloud from two points at some distance apart, in order to ascertain the height and movement of the cloud.

A disease that results from intense or glaring light; such as, snow blindness.

An instrument used in map production for producing printed names photographically.

A process of oxidation driven by radiant energy (light).

An abnormal sensation caused by exposure to light.

Characterized by or pertaining to any abnormality resulting from excessive exposure to light.