This plugin gives you the ability to have lens flare in your 3d projects. And it's procedural too; meaning you don't need to assign actual lens flare textures as long as you setup the following parameters right.
Flare Strength: How strong the effect is.
Flare Bias: Filter the brighter portions of the screen for lens flare calculations.
Flare Blur: Sort of softens the flares. Flare Bias should be decreased when this increases.
Distortion: Colour distortion of the flare effects.
Distortion Quality: Quality of said distortion.
Ghost Count: The amount of 'ghosts' that appear.
Ghost Dispersal: The spacing between the ghosts.
Halo Width: The width of the generated Halos.
Lens Dirt: Makes the final result look a little dirty. The default texture should be alright.