Originally Posted by Gipof
Is it possible for something of microscopic size to go behind the eyeball from the front of the eye, or the layers which block the larger objects like hairs etc also manage to block those microscopic objects. I noticed something on my eye, it went behind the eyelid and then disappeared completely from there. It was way too small and flat and could easily slip through a layer which manages to block just larger objects.
No, it is absolutely not possible anatomically unless you had a breach due to mechanical injury. There is a layer of membrane on the most outer part of the eyeball called bulbar conjunctiva (we can see it, the part that can get red, or we like to call it red eye when that happens) which is continuously connected and become the layer of the inner eyelid called palpebral conjunctiva. Same tissue, we just call it differently to differentiate where that structure is.
If you still suspect the tiny object is there in your eye, the best solution is to go see an eye doc for a slit lamp examination, they will evert your lid and examine it carefully with the microscope. If something is there, you usually can feel it. If you don't feel it and it's not bothering you, it may have likely fallen off but would never escape to the "back" of the eye