I can't speak for NROTC but can speak for USNA. There could be different standards but . . .
USNA does NOT want you to have any type of vision correction surgery before coming to USNA. If you do, you get "punished" from a medical standpoint. First, they take your pre-corrected vision (what it was before the surgery) as the vision they consider for admissions purposes. Thus, you get zero benefit for having had the surgery.
AND, they view vision correction surgery prior to attending USNA very unfavorably. The reason is that the Navy believes that eyes continue to grow/change during one's early college years. Thus, in their view, there is a likelihood that the person's vision will change and/or the surgery will have to be repeated (if it can be . . . I'm not an MD). Finally, as noted above, LASIK may not be acceptable for being a pilot. All of those are considered issues.
If you need better vision to be a pilot or SEAL or, quite honestly, just want the surgery -- and you meet the medical requirements to have the surgery -- you can have it during (I believe) your junior year. I would assume (but do not know) that a similar program exists for ROTC.
In any event, if you are thinking about vision correction surgery, PLEASE ensure you speak to the right people in the services before going forward. You could ruin your chances for certain programs by having surgery precipitously.