Kids these days think that lens flare was invented by J.J. Abrams. More likely, the flare effect may have been accidentally injected into "Star Trek" (2009) through the use of lucky yet tragically unwashed hipster eyeglasses. (I suppose if you wash them, they're not lucky anymore.)
Lens flare occurs when you point a camera lens into a bright light. Cinematographer Gregg Toland invented one of the first stable lenses that could be pointed directly into a light source, see "Citizen Kane" (1941). Award-winning lensman László Kovács was a most influential proponent of artistic lens flare, working from a list of movies that include "Easy Rider" (1969), "Close Encounters Of The Third Kind" (1977), and "Ghostbusters" (1984).
Finally, we can also grant lens flare honours to "Duke" Jay Forests, the uncredited creator of the lens flare filter for Photoshop, which has in its own way heralded the end of civilization as we know it. If you use it once, be sure to use it a hundred times! That only makes lens flare better.