Welcome to Gaia! ::

You're making your lines too thick and dark. For eyelashes, they're thick at the base and thin at the end, so making quick wispy-movement with your hand/wrist to achieve this look can help.

I don't know if you were, but remember to look at pictures of real eyes when drawing. If it makes it easier, even try to pop the image into photoshop and change it to black and white to practice with for a while (though, I don't suggest always doing this as it'll mess with you in the end).
you'll be able to see how the shadowing and highlights works a little better without being distracted by the colours.

Practice and keep in mind that you don't want to make all your lines the same thickness... That's not realistic at all ^^;

well, there should be some slight shading on top and bottom of the whites of the eye, because your eyeball is basically round.... so there is some shadow to it.... also, there are tiny lines in your eye, very hard to see unless you up close and personal, but i can't describe them well, ild have to draw them to show you....

the most important part of realism is not having the aspects of a cartoon within them...thick outlines really make it seem cartoonish, like you're following a guideline so you need to not focus ont he lines to create you're form, rather the shading around the places the fold and move like beneath the eye start dark with shading depending on the light you have them move out creating less intensity for the shading...

shading is what makes realism, because realism has form not line...
i wish i could show rather than tell...but that's about all that i can say

the way the eye is drawn is great, but focus on shading to make it flow rather than stopping at the the line liek you're ramming into a wall...that might make it work better

and the best thing for studying realism is simply drawing things as you see them; with the lighting, the shades and the movement they have...

hope I could have helped somehow