So these are not hard at all! All you need to do is go on google and search up "(color) eyes png" that's what I usually search up but sometimes the pic doesn't come out as a png so you have to go to PicsArt.

Then click shape crop and click the circle and crop the eye.

Then zoom in on your picture and place the eye where the faceclaim's eye is. These work the best with pics where the faceclaim is looking into the camera.

Line the eyes up with the faceclaims then Click the eraser tool and erase the parts where the eyelid is.

And if you like it like that, that's okay! Usually I lower the opacity though just so it looks a little more blended in.

Then just duplicate the image and do the same for the other eye and eyes are usually the same size so it helps with that too 😂

And there you go! That's how you do it and you can obviously do this lots of eyes colors.
So I hope this helped! Let me know if you guys have any questions!