- A stray patch of brightness in a photographic image resulting from aberrant refractions or reflections within the lens due to an exceptionally bright light source, sometimes one just outside the image proper. Lens flare is usually unwanted, but can be exploited for artistic effect.
lens flare - Computer Definition
Unwanted, excessive light in a photograph due to internal reflections and scattering of light caused by a camera lens with non-uniform optical characteristics. Zoom lenses, which contain several elements, tend to introduce more lens flare due to the many surfaces within the lens. See purple fringing and chromatic aberration.