Blender addons Blender – Flared VFX

Flared is a real-time lens flare generator that works directly in the viewport of Blender, using Eevee engine.

Flared (Standard and XT) is an add-on for Blender that generates lens flares. It is based on 3D elements and procedural textures, so it's resolution independent. It is completely real time: you can see the flares in the viewport and you don't need to use the compositor. Flared is not screen space based, so it works also when the light sources are out of the screen space. You can create as much flares as you want, there's no limit (it depends only on your hardware). Lens flares work both with Eevee and Cycles.

https://www.blenderlensflare.com/