How do you do this? I use photopea btw

I'm just beginning, but I simply paint the color of glow for the eye, burn the inner part, and dodge the outer circle of the eye. After that, I smudge it "out" (so to say). Does that make sense?

I usually paint white over the eye on a new layer, then give it a layer style (outer glow) and play with the style and opacity settings until it looks good. But I rarely do glowing eyes.

Here's the tutotial of how I've always done glowing eyes:

Its pretty basic, but its a good foundation for playing around and getting started. After I do the initial 'glow bubble' I go back on other layers and fade it out a little more, as well as adding detail under the 'glow bubble' of where the light would effect the bone structure of the horse :)

I forgot to note; the tutorial is from my DeviantArt.

You can find it, alongside other tutorials and pre-mades/cuts here:

The credit to the 'model' is also in the description of the tutorial :)