Bloom
A post-processing effect that lets very bright surfaces bleed out as a glow into surrounding pixels, mimicking light scattering in the eye and lens.
Real lenses and retinas cannot hold a crisp edge against a dazzling light source; the light leaks out around it. Bloom imitates that: you threshold out the brightest pixels, downsample and blur them with a Gaussian at several scales, and add the result back over the image. In an HDR pipeline it is a natural final step, since colours can be brighter than white before they are tone-mapped back down.
The effect broke through in early-2000s real-time graphics and became so well-liked that the middle of the decade all but drowned in glow — a stretch where every metal surface and every lamp shone like the sun. Used with restraint, it is a cheap way to suggest intensity.