it should clear up in 5 days if you're using eye drops, if not then see your doctor again. I'd imagine the school will have certain proceures they have to follow when a child or member of staff comes down with something infectious, they certainly should have so I'd double check. Although when I had it last week my doctor said it's mostly spread through using the same towels etc when you live with someone. I'd imagine you'll be fine in about 3-5 days. After the first day or so of taking the drops you'll notice the difference so just hang in there.