1. a chemical reaction initiated or accelerated by light energy
Usage: technical; chemistry
2. a biological response or change triggered by exposure to light
Usage: biology; physiology

Examples

• Photosynthesis is a fundamental photoreaction that converts light energy into chemical energy.
• The photoreaction of silver halide crystals is the basis of traditional film photography.
• Chlorophyll molecules undergo a photoreaction when exposed to sunlight.
• Scientists study photoreactions to develop more efficient solar cells.
• The photoreaction in the retina allows us to see light and color.