My baby turtle has a transparent white film over its eye that looks a bit swollen, not just the eyelid. Is this normal or is it sick?

A white film on a turtle’s eye is very likely white-eye disease, usually from bacterial, fungal, or other microbial infection. Early on the cornea turns white, the nictitating membrane reddens, and a little discharge appears inside the eye. If it worsens, corneal erosion, reduced vision, or even blindness can occur.

Treat with antibiotic eye drops or ointment such as chloramphenicol or erythromycin, and give some oral antibiotics like azithromycin. Also keep the habitat clean, change water regularly, and maintain good water quality.