I lots of have loose skin under my eyes, what is the best treatment? Laser or bleph?

Either. Laser treatment with a fractional laser is a good non-invasive way to start. If this doesn't work then you can try fillers under the eyes (or PRP under the eyes). Again minimally invasive and also effective. Reserve a bleph for a last resort or if you have very severe skin laxity.
See a plastic surgeo. You need to see a plastic surgeon to get a proper answer to this question. Without being able to see and examine you in person, it is hard to answer this question in this setting.

Related Questions

Loose skin in lower cheeks and under eyes just at an age of 21, what should I do. I can't afford laser treatment, what are the natural alternatives?

Doesn't make sense. At your age, unless you have underlying medical issues you should not have age-related facial changes. If you feel like you have abnormal skin, see a dermatologist. If you smoke, stop- this will age you prematurely. My suggestion is that if you choose to see a cosmetic surgeon, see a busy one with a good reputation who won't be tempted to offer you a procedure you won't need. Read more...