Hope you are doing good.

Nautical science requires a perfect vision.

Yes. You are right.

During the admission procedure, at the time of health checkup, you should be having perfect vision else you would be rejected.

The above guideline is compulsory.

If you are declared as having perfect vision during the admission procedure health check-up but during the course they find out that you actually dont dave perfect vision, then there would be no problem for you.

After you have successfully cleared the the admission procedure health checkup there would be no problem for you.

Hoping for your bright future.