>>Dr. Ketchum: Okay, so the next visual impairment
are called corneal ulcers. And corneal ulcers are actually an open sore that’s on the
cornea. And there’s lots of different causes for these. You could have an injury to the
eye. So you’ve poked the eye, for example. You can end up with corneal ulcers due to
your contacts as well. So if something gets behind your contacts, then you can have—bacteria
can get under there, or dirt can get under there, and it abrades the surface of the cornea.
Eye infections, okay? Different types of eye infections can cause these open sores as well.
And so how do you know if you have a corneal ulcer? So what doctors will do is they’ll
take and they’ll, they’ll put a dye in your eye. So if you see on this bottom picture,
there’s a little bit of yellow coloration. So they put this dye in there and then it
fluoresces wherever that cornea is.