To me, it looks like parasitic activity. Has your eye doctor or dermatologist ever mentioned parasites as a cause?
Getting into the scientific names of the different types of parasites can become overwhelming. Nonetheless, I want to refer you to two websites to give you an indication of the some types of eye parasites that exist. Dirofilaria, Onchocerca Volvulus and Toxocara Canis are three main categories of parasites that can affect the eye. The Onchocerca Volvulus looks, to me, like the type of parasite that may be affecting your eye. You can check it out at the following address: http://www.cdfound.to.it/html/onc1.htm In particular, look at the picture labeled, onc 2c-ic. This looks like the type of larvae activity (shape) occuring in your eye lids.