Retained Shed Indentication and Treatment

[d_virginiana]

They can be. They can be very serious. They can cause blindness/loss of the eye/life threatening infection if the eye.

Would they normally cause problems that bad between one shed and the next, or is that more if it builds up over several sheds like the cobra that was mentioned?
Any suggestions on how I could tell with a blind snake? His eyes, especially his left one, are very clouded by what appear to be cataracts, and are almost always 'murky' and dark looking. I try to find the eyecaps on every shed, but sometimes they're mangled too badly to tell. I always worry that something bad is going to happen if I miss one.