How to Care for a Swollen Eye on a Red-eared Slider Turtle. The red-eared slider turtle can be distinguished by the red markings on the sides of its face. Red-eared sliders are appropriate turtles for beginners because they are not fussy about temperature and are easy to keep. However, swollen or puffy eyes -- which may be caused by a bacterial infection, a scratch from another turtle, chlorine or a vitamin A deficiency -- are a common ailment among domestic turtles. You can care for your red-eared slider's swollen eyes with the help of your veterinarian. Instructions 1 Take your red-eared slider to a veterinarian that specializes in reptiles. She will diagnose the cause of the swollen eyes. The two main culprits are a vitamin A deficiency or a bacterial infection. If the vitamin A deficiency is not terminal, the turtle should make a complete and rapid recovery. 2 Treat vitamin A deficiencies with an injection. You will have to alter your red-eared slider turtle's diet to include foods rich in vitamin A. Your veterinarian can advise you on ways to improve your turtle's diet. 3 Confirm bacterial infections by asking your vet to test the mucous around the turtle's eye. The vet will then give the turtle an antibiotic injection and possibly an oil-based ointment that should be applied with a cotton swab. Bacterial infections are usually caused by poor environmental conditions. Clean your red-eared slider's environment and improve conditions by cleaning or replacing the filter, checking temperatures and keeping your vivarium clean at all times. 4 Check your red-eared slider's water for chlorine. Chlorine can cause the eyes to swell. Dechlorinate your turtle's water with a few drops of dechlorinator available at pet and aquarium stores. Dechlorinate the water every time you change it.