Definition

1. Adjective:
   • Reacting to or affected by light: Describes a material, substance, or biological system that undergoes a change or responds when exposed to light, especially visible light.
   • Having a property that changes with light exposure: Often used for materials whose chemical or physical state is altered by light, such as photographic film or certain electronic components.

Usage Examples

• Adjective:
  • Photographic film is light-sensitive and must be kept in a dark container.
  • Some people have light-sensitive skin that burns easily in the sun.
  • The device uses a light-sensitive cell to automatically turn on the streetlamp at dusk.

Advanced Usage

• Scientific/Technical Context: In biology and medicine, it can describe cells, like those in the retina, or conditions, like photophobia.
  • The patient's light-sensitive eyes required her to wear sunglasses indoors.
• In Chemistry and Materials Science: Refers to compounds or coatings that react photochemically.
  • The light-sensitive coating on the silicon wafer is essential for the lithography process.

Variants and Related Words

• Photosensitive (adj): A more technical synonym, often used interchangeably with "light-sensitive," especially in scientific contexts.
  • The patient was diagnosed with a photosensitive rash.
• Photoreceptive (adj): Specifically describes biological cells or systems capable of detecting light.
  • The photoreceptive cells in the plant's leaves help it track the sun.

Synonyms

• Photosensitive: Reacting to light.
• Photoreactive: Undergoing a chemical reaction upon light absorption.

Related Phrases and Compounds

• Light-sensitive paper: Paper coated with a chemical that changes when exposed to light, used in photography and blueprinting.
• Light-sensitive resistor (LDR): An electronic component whose electrical resistance decreases when light intensity increases.

Adjective

1. sensitive to visible light
   • photographic film is light-sensitive