What causes a tiny bump in the corner of the whites of someone's eye?

It sounds like you are describing a pinguecula and it is caused by prolonged exposure to ultraviolet (UV) light. (ie-spending too much time outdoors without wearing sunglasses) We see this more commonly in the southwest region of the USA and for some reason Hispanics tend to develop them more rapidly than caucasians.

There is no form of treatment unless it progresses to a pterygium. As the pterygium grows and gets close to the center of your vision, it can be removed with a surgery. But it's always best to never let it get to this point.

I recommend looking these two things up on Google pictures and you will have motivation to wear sunglasses outside to prevent the pinguecula from converting into a pterygium.

Source: I am an Optometrist in Arizona. (I see this daily)

hi, i don't know exactly what causes them, but i myself have had one on the white of my left eye. It seemed to just appear as I've never noticed it uptill a few months ago but i haven't had any trouble with it and its never gotten any bigger.