Have you ever thought about what it takes to be an astronaut? Or wondered whether you could become an astronaut, even though you don’t have perfect vision and you wear contact lenses?
With space exploration in the news, thanks to NASA, Elon Musk, and others we dive into this exciting area as it pertains to vision correction and contact lenses. In this post, you’ll learn about the vision requirements for astronauts, and whether you can wear contact lenses in space, among other things.
Vision requirements for astronauts
During the early days of the space program, NASA astronauts were required to have natural 20/20 vision and were not allowed to wear corrective lenses of any kind. Fortunately, NASA has since loosened these restrictions.
However, there are still many intense vision requirements to becoming an astronaut. Although NASA no longer requires astronauts to have naturally perfect vision, their vision in both eyes must be correctable to 20/20.
For astronaut pilots, vision requirements are more demanding. Astronaut pilots cannot be colorblind. Only non-pilots and mission specialists are given leeway when it comes to color blindness.
Contact lenses in space
Since astronauts aren’t required to have naturally perfect vision, can they wear corrective eyewear such as contact lenses in space?
The answer is: yes, you can wear contact lenses in space. There are already astronauts who wear contact lenses or prescription eyeglasses. Figures show that approximately 80% of NASA’s astronauts wear some type of corrective lens.
Here’s what an actual NASA astronaut Marc Garneau has to say about wearing contact lenses in space:
“The answer is yes, you can wear contacts in space. Some astronauts do wear them. And to become an astronaut – if you’re going to become a pilot astronaut – you have to have better than 20 over 70 vision distance, and it has to be correctable to 20/20. If you want to become a mission specialist – the other kind of astronaut – your vision requirements are 20 over 200, once again correctable to 20/20. So you don’t have to have perfect vision to become an astronaut.”
Contact lenses designed for space travel
In space, where there is only a minuscule amount of gravity, liquids, solids, and gases behave differently. This means contact lenses perform differently in space than they do on earth.
This led Paragon Vision Sciences, Inc., an Arizona-based manufacturer of specialty contact lenses, to partner with NASA’s Langley Research Center in 1993 to perfect a process for developing contact lenses.
The result of Paragon and NASA’s experiments was the Hyperfuried Delivery System (HDS) contact lens. HDS contact lenses gas-permeable contact lenses, so they don’t contain water. They are resistant to deposit and bacteria buildups. They are also rigid, allowing them to maintain their shape and making them easier to handle than soft contact lenses. Furthermore, Paragon’s HDS contact lenses are much more oxygen-efficient than other types of contact lenses.
The FDA has approved HDS contact lenses for up to seven days of continuous wear.
Impact of space travel on vision
According to NASA, vision problems and eye structure changes in astronauts are due to the microgravity in space and its effects on intraocular pressure. NASA also examined several astronauts and found vision issues and eye structure changes in all of them. Changes occurred in the eye structure of astronauts included flattening of the back of the eyeball, and to the retina, and optic nerve, as a result of a lack of gravity.
NASA believes that living in microgravity conditions for extended periods is the reason astronauts experience long-term vision problems. In the course of their research, NASA found that space travel lasting six months or longer can have long-term negative effects on vision.
On Earth, the effect of gravity pulls our fluids towards our lower body. Meanwhile, In space, fluids float toward the head, resulting in fluid shifts in the eyes, which is what leads to vision problems for astronauts.
NASA performed a survey of 300 male and female astronauts and found that 23% of short-flight astronauts and 49% of long-flight astronauts suffered problems related to both near and distance vision. For some of these astronauts, the vision problems persisted for years after they returned to Earth.
Astronauts suffering long-term or permanent vision issues suggest that a significant percentage of NASA’s astronaut force wear contact lenses or prescription eyeglasses. One can assume that it may become more common for people in space to wear contact lenses.