If I recall correctly, they are suppose to dry out first then the next rain storm the egg case sort of melts and the baby snails drop to the water. My main concern would be the lights cooking the eggs.
I have applesnails. If you want them to hatch: water temp. is good at 75*, and if you are worried about them getting too dry put a piece of thin plexy-glass [it is actually plastic] over that part of the tank. They should hatch in 2 to 4 wks. And I put a little piece of mesh on the tank very close by with food in it. Being very tiny, you don't want them traveling far to eat. I use a piece of one of those 'week end feeder' foods for tropical fish. Also, I put a chunk of 'cuttle bone' they can eat for calcium source for their shells. And once they hatch I take a few to another tank. Otherwise the adult snails usually eat them, or they actually will eat each other, because they all hatch within 12 hours or so it seems. I hope this helps, and wish you good luck. They are so very tiny and cute ! Oh- I learned most info from www.applesnail.net
Serg, you need to move the eggs. Keep them near the lights and they will REALLY dry out killing the embryos.
I just scrape the eggs off with a razor blade carefully and wrap them in damp paper towels and then stuff inside a container to trap humidity inside. Float the eggs in your tank if you want or stuff inside a cabinet. Wait for 3-5 weeks. If 5 weeks lapse and the eggs remain pink, dispose them. They should turn blue near hatching period.