I'm a bit worried.

[Mikkisaur]

Friday, I noticed that Gramps looks... off. His eyes are protruding a lot farther then Comet's, he has some kind of white.. stuff near one eye, his head looks almost rusty, his color is all faded and his fins have splotched of different color. I know Gramps is a bit old, probably 2.5 - 3 years old. Right now, he's in a half gallon drum bowl because I'm waiting on a bigger tank to cycle. It doesn't have a heater, thermometer or filter (I know, I know.) but I try to leave a warm lamp on during the day for them. They get Top Fin betta pellets twice a day, about two or three pellets per meal. I usually do 50% water changes every other day, adding some aq. salt since I noticed something wrong, and water conditioner. I haven't tested the water. Does anyone have a clue as to what's going on?

ETA: I forgot to mention: His fins look a bit ragged, and his bum sinks when he stops swimming. Also, it might help to mention that despite all this he consistently makes bubble nests and flares quite a bit.

[Bombalurina]

Google a picture of pop-eye - does it resemble that?

What he really needs right now is a good, steady temperature. Whilst the lamp is a nice idea, it's going to be causing big temperature swings everytime you turn it on or off, so I would just leave it off for now. Try to get the temperature as stable as possible. To keep the bowl warm, wrap it in a towel or jumper.
If you can, as a temporary QT tank, set up a storage bin over a gallon. 3 gallons is easy to get and they are very cheap. Best of all, they can be safely heated. Add in some decor like a coffee cup for him to hide in. :)

Sorry I can't advise too much on treatment (warm, clean water will work wonders, though!) as I'm not familiar with most of the medications available on your side of the world. Hopefully someone else will come along soon. :)

[Mikkisaur]

It doesn't look like the pictures of pop eye at all... Those are huge O.o" Maybe it's normal for him, seeing as I got him off my bother earlier last week. I do have a big tupperware type container that looks around 3-5 gallons. I'm really not sure how to heat it, though.

[Bombalurina]

If you can afford just a normal 25watt submersible heater, that will do the trick. :)

[Mikkisaur]

Thing is, I can't :\ I rely on my parents for getting to any lps or lfs and things are shaky around here right now. I'm flat broke on top of that, or else they'd already be set up in the new tank.

[Pataflafla]

If he has bulging eyes, it could be him just having big eyes or there could be some swelling due to age since 3 years is usually the maximum life expectancy.

For both the bulging and the sinking issue, epsom salt will help at 1 tsp/gal, but a regular temperature will help more since that could be causing the sinking.