Amongst the various requirements that Navy SEALs must meet in order to begin their training, vision is one of the most important requirements. Due to the unique nature of the Navy SEALs and the variety of settings and environments which they will work in (sea, air, land, etc.), they are required to have excellent vision.
When you are going through the screening process to become a Navy SEAL you will be required to take part in a vision test. If you fail this test you will not be permitted to train to become a Navy SEAL. The Navy is very strict about these rules and make no exceptions. However, it should be noted that if you do in fact fail your vision test that you may be able to receive PRK Refractive Surgery. However, you will need to ask your recruiting officer if this applies to you.
All Navy SEALs must have 20/20 vision or be able to have their vision corrected to 20/20 vision. Uncorrected vision is acceptable if it not worse than 20/200 in each eye. To determine the specifics of vision requirements you should personally speak to your recruiter before undergoing any type of surgery or before taking part in a vision test.
Many people do not take their vision into consideration when they sign-up to become a Navy SEAL or to even join the Navy. However, you must pass a vision test along with other physical exams before you can even be accepted.