Turtles/Red Ear Turtle
I have two turtles that are in the same 10 gallon tank. One you can clearly see eyes on the other one you cannot see eyes. It looks like the other one has a film around both of its eyes. What do I do? Or do you happen to know if there is something wrong?
You need to get your turtles into a bigger tank. A 10 gallon tank is too small for even one hatchling RES. If your turtles are bigger than hatchlings, then the tank is way, way too small. When a tank is too small, it's impossible to give the turtles adequate swimming or basking room, and you just can't keep the water quality up, even if you have a decent filter.
So the first thing is to get a bigger tank. You didn't say how big your turtles are, but if they're hatchlings, you should have at least a 30 gallon tank (for now)--however, mature RES need very large tanks and in a few years you are going to need at least 150 gallons, so if at all possible I would get a big tank now rather than later because that way you don't have to upgrade to another filter. You need an external canister filter capable of handling double to triple your tank's capacity, so for a 30 gallon tank you need a filter sized for 60-90 gallons. Adequate filtration is extremely important. Poor water quality is probably the #1 reason for skin and shell infections, and is likely the issue with your turtle.
In addition to tank size and water quality, you need to make sure your basking and water temperatures are correct. The basking area surface should be around 88-90 degrees, and the water should be 76-78 degrees for hatchlings, and a few degrees cooler for larger turtles. You also need a source of UVB (not UV, but a special reptile bulb). Without UVB, your turtles can't metabolize calcium and can develop shell and bone deformities.
Make sure you're feeding a varied diet that includes pellets, animal protein, and greens. Variety is important to make sure there's adequate nutrition.
Make the corrections I outlined above, and see if the eyes improve in a couple of weeks with cleaner water and proper setup. If you don't see adequate improvement, you should take your turtle to a vet for treatment.
Here's some links that outline proper turtle care in greater detail: