I found this from melobster.com
Q: While visiting an aquarium in Maine, I was told that a lobster will grow an extra "smeller" when they lose an eye. Is this true?
A: If a lobster loses a claw or an eye, it is able to grow another, although the new one is usually smaller in size.
I have read that it may take a few molts and they eye will be smaller at first growing bigger with each additional molt.