>>7781825
starting with a realistic eye is quite challenging. You haven't even figured out how to blend colors?
just practice blending them on their own, without a drawing.

this guy's vid covers it better than I could in text here. this is how I do it

>>7781830
*the link
https://www.youtube.com/watch?v=xwoZoUj9kuE

>>7781825
you need to understand the volumes and planes of the eye. look at photos, illustrations from others, and ideally 3D models. You need to understand which parts stick out, and which ones sink in (like the entire eye socket), and have learned how to shade volumes (cylinders and spheres specially), so you can apply that to the eye area instead of just winging it and "I think it's supposed to be darker below idk".

My approach to shading/blending involves first laying big patches of value, kinda like what you've done with a hard brush, then blending. Everyone has their own way of doing blending, but the way I do it is with a soft airbrush with pressure opacity, and just painting along the edge between the 2 colors and color-picking constantly. You need to be careful though, you don't want to smooth out the entire area into mud, just soften the transition.

It's also way easier (at least for me) to do this in grayscale, rather than trying to balance both brightness and good colors at the same time.

Don't try to blend two colors on the same layer together. Have the shadow on a seperate Multiply layer and erase to get soft edges.
If your drawing doesn't look nice with only lineart+flat color, adding shadows won't save it.

>>7781825
paint some basic spheres or other basic objects and leave the eye painting for later