How to remove glasses from a photo, hand retouching
I will describe my work on one job, with a non-standard task — to remove the glasses from the photo.
I did the work in Adobe Photoshop and used a Wacom graphics tablet to draw the details.
First of all, assess the photo, see how we quickly perform the work, because we have the glasses on the photo with a wide frame and overlapping about 1/3 of the eyes, there will have to do without hand drawing. Of course, you can copy the eyes from other photos of the person (if we have them available) or take the eyes from another person’s photo. I didn’t have a photo without glasses and I couldn’t use someone else’s eyes as a matter of principle.
Original photo:
Start «stamping» to remove large parts, you can remove a lot of parts this way, but when it comes to unique parts, «stamp» is powerless, as well as other tools with similar action. See what you can remove:
The most interesting and challenging part is to take a pen tablet and start redrawing the missing details, remove the rest of the frame, look at the colours, and draw the pupils, eyelashes, eyelid and other details, gradually increasing the detail.
I work on shadows and highlights, not forgetting skin texture and eyelid folds. I draw the pupils, dropping the right eyebrow a little lower (with plastika tool).
I bring the detail to a level where it is difficult to identify hand «drawing», continue to grind. Remains a small glare on the right eye, which I no longer have time for, and I decide to leave it. I continually increase/decrease the work to identify areas of excessive detail or the opposite — blurring.
I draw shadows on the bridge of the nose, make minor corrections, do some colour correction and get the result:

Before/after photo:

Update 2023:
Since a lot of time has passed since the execution of this work and the result has long seemed weak to me, I decided to take the original and redo the work, based on new knowledge and increased experience.
It came out much better, just did not waste time on the exact selection of pupil colour, as I did for myself and to see the progression of their skills
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Such detail retouching depends more on drawing skills (knowledge of shape, shadows, colour) than on graphic software skills, because even such a «powerful» Photoshop tool cannot re-create non-existent details, it always depends on the person, not the software.
I hope this article will be useful to people engaged in retouching or other activities related to photography.