Hi,
I had a similar problem about 10 years ago, in a T. albolabris (or at least that's what it was being called...). It was a youngster, maybe 1.5-2 yrs old, female. I'd suffered the usual hassles to get the thing feeding like a champ and well beyond bits of mice, so was rather attached to her.
The problem manifested as a very sudden "popeye" that was cloudy and grossly swollen - looked just like yours. I farted around a couple days hoping it would resolve itself - it didn't, naturally...
BTW, I'm seriously anal about checking every single shed for 2 spectacles - if one's missing I get right after it before it dries on hard. This was not the case with this animal.
I lived in a very small town but was lucky to have a "sporty" vet who agreed to have a look (my first trip to a vet with a "hot"
. He isofluoraned the animal down and I held her while he inspected her very closely (in the mouth, vent, and all over the outside). He then hit the books with me looking over his shoulder and answering questions.
He settled on plugged lachrymal duct as the problem (you can see evidence of these ducts in sheds). He elected to remove a little window from the spectacle (which was safely up off the eyeball due to the swelling) - used a scalpel to cut a little isosceles triangle (small side on the bottom) from the spectacle. He irrigated the gook from the subspectacular void - just used a needle & syringe, carefully - it was a lot of gook, basically pus from a bacterial infection).
I then took the animal home and gave her a couple weeks of Baytril injections. She recovered fine, kept the eye, kept her sight, resumed feeding just fine. Great outcome.
I think the whole ordeal cost me about $250 (vet time, anesthesia, drugs, misc expenses). The snake had cost $40. That's how it goes.
I've only had 2 other occasions to take snakes to a vet - for respiratory diseases they had upon delivery (grr). An adult male Vipera l. gaditana, and an adult male C. r. ravus. These also involved anesthesia, exams, labwork, and then Baytril injections for a couple weeks, and also had 100% satisfactory outcomes. Both went to the same vet, but a different one from the first (different side of the country, in fact).
Get the animal to a vet, pronto. Nothing is gained by delay.
Best luck,
Jimi