Answer all these questions as best you can (cut and paste):
1. What species ? How long have you had the frog(s) and where did you acquire them ?
2. What are your temperatures (day and night - highs and lows) and how do you measure those temperatures? Does the vivarium have any supplemental heating, and if so, what type?
75day 70night anolog. No
3. What lighting is on the enclosure (brand, type, wattage) and does the lighting add heat to the vivarium?
"Day" colored grow light Brand Sondiko
4. What is the Humidity like (percentage or guesstimate)? What type of water are you using? What is your misting procedure (automated or hand mister, how long and how often)?
75-85%. Distilled. Hand 2x a day
5. Describe your tank/enclosure and its lid or top, and give details about the ventilation (how many vents, where are they positioned, how large are they).
Zilla 20gallon live moss, pothos, cork tubes
6. What kind of food are you providing, how much and are you dusting it? What superfine powdered supplements (brand and exact product name) are you using and are they fresh (i.e. how long has the container been open, and how is it stored)?
Hydei fruit flys. ReptiCalcium. Stored in freezer
7. Any other animals in the enclosure currently or recently? Tankmates / other frogs ?
4 dendrobates and 4 mourning geckos
8. Any type of behavior you would consider 'odd' ?
No eating normal acting normally
9. Have you handled or touched the frogs recently ? Any cleansers, paint, perfumes, bug sprays etc near the tank ?
I did to observe the eye more closely and used latex free gloves
10. Take pictures of EVERYTHING -- the frogs, the enclosure, the vents. Take numerous pics of everything - that will be of great help.
If I had to hazard a GUESS (and that's all this really is for me), it looks to me like it was an injury that's become infected.
Your 20 gallon tank isn't large enough for 4 Dendrobates tinctorius, let alone 4 tinctorius and 4 mourning geckos. Mixing species, particularly for a beginner, is a really bad decision as you don't know the life habits of either species well enough to know when there's an issue starting. Mixing species is a bad idea regardless of experience but it's even worse for people who are new to keeping a species.
in the limited pictures you've provided it looks exceedingly wet, this will harbour bacteria that could cause an infection. I don't see any leaf litter or dry areas for the frogs to get to in order to be drier if they want to.
If I were to guess without consequence, the corneum groove around the eye is very visible and makes me wonder if some tear away mishap in shed manipulation while pulling into the mouth to eat occurred, and its degrade and constriction in a growing froglet in these circumstances instigated an infected pustule.
I think its worth noting that sometimes moisture is accentuated reflectivity per artifact of photo.
But the shot itself, with its accurate report and outcome is valuable.
I might've also missed some posts, but four dendrobates tinctorius in a 40 gallon is still far too small.
I would keep only two tincs in 40 gallon or 20 gallon otherwise they'll fight to the death, most likely.
This is not even mentioning the 4 mourning geckos, they definitely will need their own tank.
Here is a great post about keeping geckos and mourning geckos. https://www.dendroboard.Don't keep terribilis with mourning geckos
Whomever said it was a funky shed was correct i believe. Was able to put on gloves and it very easily wiped away. Considering the advice in this thread I've ordered a 36x18x18 with a dart frog kit from Josh's frogs.