What happens if a spider bites your eyelid

Depends: On the toxicity of the spider. Most spider bites cause mild redness and swelling. Certain ones, notable the brown recluse spider, can cause massive tissue destruction.

Pain, swelling: This depends on the type of spider but most spider bites are ordinary house type and there is a small amount of local pain, itching , swelling and redness. It this was a brown recluse spider, really unusual as it tends to hide in house corners and is more likely to bite some other part of your body, but if it occurs, then you should get to an er or an ophthalmologist pronto.