Stress from constantly keeping a facade when interacting with goyims which they are conditioned into ignoring. Stress augment blood pressure and constant overpressure end up stretching the blood vessels around and on the eyelid, which are very thin compared to the rest of the body so the effect are apparent.

It also appear on peoples with chronic sleep issues and long term depressive individuals, but its obvious the Jews do not fall into these two categories.

There is also the possibility that these traits are compounded by the hightened frequency of genetic disease among the Ashkenazi jewish population like Thyroid eye disease also called Graves' ophthalmopathy, which has a genetic origin in the crushing majority of cases recorded.

Pic related.