I recommend placing your cham in a shower on a plant for around 30-45 minutes. Make sure it is lukewarm and let the soft spray land on 75-85% of your plant. That way your cham has a little spot to temporarily hang out. Try to keep your cham in the H20 most of the time. This is just step 1 to...
Here are some potential signs:
1. Eyes closed. (One or both. They may also open and close periodically)
2. Staying at the bottom of the cage
3. Bubbling at the nose and mouth
4. Shed not completed
5. Lethargic
6. Poor aiming with tongue
7. No use of the tongue. Just biting/lunging at feeders.
8...
Try placing the cham in a shower for 30-45 minutes to hydrate and possibly flush the eyes. It is natural for them to not eat for a while, but if they do not drink; that is a problem.