Can I be an astronaut if I have myopia?

Being an astronaut is the dream job of a lot of people. After all, who wouldn’t want to look at the stars from outer space? Since having sharp vision is important for traveling through the milky way, it’s totally possible for someone with managed myopia to be an astronaut.

So before you buckle up and prepare for takeoff, make sure you have your glasses ready. Because although I haven't been to outer space myself, I imagine it’s a sight to see.

Can astronauts have myopia?

Yes, NASA astronauts can have myopia and still go to space. As a matter of fact, approximately 80% of astronauts wear glasses or contact lenses to correct some sort of vision problem.

To be approved for space travel, astronauts must have 20/20 vision or better, with or without correction. This means that they can see clearly, without blurriness or double vision.

If an astronaut has a refractive error that causes them to have blurry vision at certain distances, it must be correctable to at least 20/20. These refractive errors can be corrected or managed using glasses, contact lenses or vision surgery. They include: 

• Myopia (nearsightedness) 

• Hyperopia (farsightedness) 

• Astigmatism (visual distortion at all distances)

• Presbyopia (age-related farsightedness)

To apply to become an astronaut at NASA, you must also have or meet the following requirements:

• U.S. citizenship

• A degree in engineering, biological science, physical science, or mathematics

• At least three years of related work experience

• Ability to pass the NASA long-duration space flight physical

• Blood pressure of 140/90 or lower

• A standing height of 62 to 75 inches

For would-be astronauts who don’t want to mess with glasses or contact lenses in space, NASA has approved LASIK and PRK for the correction of refractive errors. LASIK is a surgery that uses a laser to fix blurry vision so you won’t have to rely on glasses. 

If you’re interested in refractive surgery, keep in mind that you have to be at least 18 years old to have LASIK done. NASA also requires you to wait a year after the surgery before traveling off-planet, and you must be free of any side effects related to the surgery.

SEE RELATED: Can you be a pilot if you wear glasses?

How outer space affects eyesight 

There is a growing number of astronauts who have gone into space with 20/20 vision, and returned home with poor eyesight. 

Astronaut John Phillips noticed his normally clear vision had become fuzzy while in space. When he returned home and had his post-flight physical, eye doctors found that John’s vision had gone from 20/20 to 20/100 in only six months.

Additional testing showed that the state of his eyeballs had changed, not just his eyesight. He was diagnosed with a condition called visual impairment intracranial pressure syndrome (VIIP), now known as spaceflight-associated neuro-ocular syndrome (SANS).

Here’s how it happens:

When you’re on earth, there’s gravity that keeps you from floating up into the sky. It also pulls blood and other bodily fluids down toward your feet. In outer space, there is no gravity, which causes extra fluid to travel upward, toward your head.

Having extra fluid in the skull causes a rise in pressure — like filling a water balloon with too much water. The pressure can affect your brain and the backs of your eyes. 

When Phillips had his eyes examined, the backs of his eyeballs were flattened, and his retinas (the tissue at the back of his eyes) were pushed forward. His optic nerves also showed signs of inflammation.

Finding a solution to SANS is tricky because the condition only occurs in people who have been to space. However, new research seeks to allow current and future astronauts to travel the solar system without putting their vision at risk.

READ MORE: Space changes your eyes in some pretty unnatural ways

Page published on Monday, March 14, 2022

Medically reviewed on Saturday, February 12, 2022