Without more information it is hard to answer. Has snake shed recently? Is it going into shed? What are you humidity levels and temp levels? How old is the snake and how long have you had it? As Chained said, pic would also help.
the pic is really blurry...but pairing that with your humidty dropping that low, id GUESS at dehydration. my unexperianced advice would be to give her a nice soak in 85 degree bath, and try to get the humidity up in her tank some.
Q: Help, My snakes eye has a dent in it!
A: Don't panic. This occasionally happens and can be attributed to the snake being a little dehydrated. Make sure it's got fresh water and a bowl that it can soak in. The dent should be gone with the next shed cycle.