Nice job, Neb
There are two little things that I noticed:
1) The right eye has a straight-edged highlight above it. As we don't expect to see anything straight there, ends up looking a bit like a band-aid. A bit of a curve here would look more natural;
2) The original image has a slight yellowish tinge, whereas the retouched parts are a more pure grey. You could fix this now either by desaturating everything, or by copying the colour from the image to the retouch (using a brush with mode set to "color"). You could, however, have avoided this problem all together by converting to greyscale right at the start - before retouching anything.
Hope this helps a little, all the best,