So I noticed that whenever my tortoise is waking up she's got trouble opening her left eye. I didn't really notice any gooey stuff but it doesn't look natural or like it is supposed to happen...
I can't see your entire enclosure, but from what I can see it looks pretty dry in that enclosure for your redfoot. What is your humidity at? Sometimes these guys have trouble opening their eyes when its too dry. Give her a soak and let us know what your temps and humidity are at (or direct me to the thread if you've stated this previously).
Go to petsmart or a place like that and pick up a hygrometer and place it inside the enclosure (probably best on the substrate) and you can get a good idea of the ground moisture level
Without a hygrometer reading, none of us can tell if it's too dry in there or not; however I'd bank on it being a bit too dry for your redfoot based on the surrounding substrate that I see in your picture. Things should not be sopping wet, but your substrate looks pretty dry. You can pick up hygrometers at a pet store (as previously mentioned) or on many online web stores and you might consider this option. A lot of us run humidifiers or modify the enclosure to boost the humidity. It can be as simple as integrating some of these ideas (http://tortoiselibrary.com/ - see housing and humidity) and covering at least 70% of the enclosure.
Constantly wet substrate can lead to shell rot. You want a humid environment with moist or slightly dry top layers of substrate. The information provided in the link above should provide some starting information to achieve these conditions, feel free to ask us more if not.