From the psychological perspective
The loss of an eye is initially a shock.
After all, the eye helps communicate our surroundings to us in a few swift glances. That said, the eye is far more than merely the communicator of this purely optical perception.
The most fitting formulation probably came from the German dramatist and author Gerhart Hauptmann (1862-1946): “Eyes speak louder than lips.”
All our feelings and moods can be read by looking into the eyes.
Against this background the question soon arises: “Can anyone see that I’m wearing a glass eye?” This uncertainty can make for an enormous degree of psychological stress.
The custom manufacture of an optimally fitting ocular prosthesis means the answer to this question is quite simply “No”.
The loss of the natural eye is not evident to outsiders. This means the psyche can breathe a sigh of relief, self-esteem is strengthened again and any uncertainty in terms interacting with the person opposite disappears.