Why are some eyes deep set and others seem so big they bulge?

People have different size globes (eyeballs) which is often an indicator of being near- or farsighted (myopic and hyperopic).

Hyperopic eyeballs are almost by definition smaller than normal, having failed to grow to the normal size (+23.0 mm). While vision can be normal in their younger years thanks to the compensating effect of accommodation, hyperopes will eventually lose their good uncorrected near and far vision. One can often recognize hyperopes by how deep set their eyes are.

Myopic (nearsighted) eyeballs are larger than normal, so they may appear quite prominent and even to bulge somewhat. It is this larger than normal size eyeball that makes people nearsighted: they can see up close but not far off without glasses or contacts.

An interesting aside from Genesis 29:17:

Leah had weak^[a] eyes, but Rachel had a lovely figure and was beautiful. ¹⁸ Jacob was in love with Rachel and said, "I'll work for you seven years in return for your younger daughter Rachel."

Footnotes

1. Genesis 29:17 Or delicate. Some sources say "beautiful."

How could "weak eyes" also be seen as "beautiful eyes?" My own theory is that Leah was nearsighted. Her "weak eyes" meant she could not see well but were also considered "delicate" or "beautiful" in being larger than normal. Big and prominent eyes are often used in painting and drawing to imply beauty and interest!

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic