Same problem, but solved
Your chameleon has an eye infection. I have a Jackson's chameleon with the same problem, but he's now almost out of danger after treatment.
Many people told me that it could be a vitamin A deficiency, but this is not correct. Vitamin deficiency is in both eyes.
I couldn't afford a vet, as this could easily go into hundreds of dollars, but I researched and treated my cham at home, with great results. I bought Reptaid from Amazon, which is a must, and an antibiotic. Here's the link for the antibiotic.
http://www.beardeddragon.co/index.php?route=product/product&product_id=479
My Jackson's chameleon had an extremely swollen eye and a respiratory infection, also what i believe to be the beginning of stomatitis. His eye was so puffy, it looked like it was about to explode, and he had reached that RI stage when his breaths turned into hisses; the advanced stage. I started him on Reptaid, and it kept him afloat, but no improvement was shown. The I started the Enro, orally, not via a nebulizer. I used an eye dropper to put 4 drops of Enro in his mouth twice a day (12 hours interval, approx.) My husband helped by holding the cham and i used my fingernail to pry his mouth open, as gently as I could. He didn't like it, but he soon got used to it. After making sure that he swallowed the drops, I used a small syringe (without a needle) to pour 1ml of water down his throat. Half of it spilled out, but at least i got some water into him. It is essential to give the cham at least 1ml of water every day when administering antibiotics, as he is at risk of kidney failure if this important step is not followed. I also continued with Reptaid, at least once a day, and fed him wax worms, some of which i tossed in probiotic powder first. Since my cham only eats moving prey, and the worms weren't moving much, I opened his mouth and put a couple in it. He ate them right away. Wax worms are known as the candy bars for chameleons, and I shouldn't normally feed them to my cham every day, but in this instance they proved to help a lot, as he wasn't eating anything else, and I provided him with nourishment. I already finished a 5ml bottle of antibiotic, and since my cham is not yet out of danger I will start him on a second bottle. It is very important to continue the antibiotic at least a few days after you see improvement, otherwise the infection can return or the bacteria could develop resistance to the antibiotic. So, if you need to treat your reptile for infection, better to buy at least 15ml of antibiotic for a chameleon. My boy weighs 60 grams, and I had to give him, as I said, 4 drops of antibiotic twice a day in order to see any improvement (that's about twice the recommended dose).
His eye swelling is now almost gone.
I hope this helps.
