5 years after cataract surgery. Shld I do something? Anything to worry abt? It's been 2 yrs since my last checkup. Not much changes with vision.

Absolutely yes! There are many silent causes of blindness that can occur months to years after cataract surgery, and you should have annual dilated ophthalmological examinations. You can't be certain that your eyes are healthy just because you think that your vision is unchanged.
Yes you must. There could be capsular changes that can be easily managed to improve your vision. Retinal health and pressures should be reviewed too.
No worries. Cataract surgery at age 15 is very unusual. This is often due to trauma, metabolic diseases such as diabetes, or hereditary factors. As long as you are seeing well, problems late after cataract surgery are uncommon. However, if your cataract was due to trauma or a metabolic condition, then other issues can arise with time that have no symptoms, such as glaucoma. A full eye exam yearly is prudent.