Have you ever gazed at the night sky, dreaming of becoming an astronaut, but wondered, “Do you need 20/20 vision to be an astronaut?” Worry not! Achieving the stars is not limited to those with flawless eyesight. Vision is essential in space exploration, but options and opportunities exist for aspiring astronauts to overcome visual challenges and reach for the cosmos.

In this blog post, we unveil the truths about vision requirements for astronaut candidates, explore various vision correction options, and discuss the role of vision in space exploration. By the end, you’ll understand what it takes to embark on a successful space career, even with a less-than-perfect vision.

Key Takeaways

  • NASA has established vision requirements for astronaut candidates, which must be met to pursue a career in space exploration.
  • Vision correction options such as LASIK, PRK, contact lenses and glasses are available for aspiring astronauts with less-than-perfect vision.
  • Regular visual acuity assessments throughout an astronaut’s career are necessary to ensure mission success and personal health.

Vision Requirements for Astronaut Candidates

Astronaut candidates in NASA astronaut office

Space agencies such as NASA place great importance on visual acuity for the safety and success of their missions. Consequently, they have set specific vision standards for astronaut candidates. These standards cover uncorrected and corrected visual acuity, necessary for tasks like operating jet aircraft and participating in spacewalk training.

Understanding and meeting these requirements is the first step toward becoming an astronaut. We will review the details of uncorrected and corrected visual acuity standards for those aspiring to travel in space.

Uncorrected Visual Acuity

Contrary to popular belief, perfect uncorrected vision is not a strict requirement for aspiring astronauts. NASA, for instance, sets certain limits for uncorrected visual acuity. If an individual can read the smallest line on the Snellen eye chart, they are considered to have 20/20 vision, which is required for the astronaut office.

However, the uncorrected visual acuity standards vary depending on the position. Third-class medal certificates, for example, necessitate a visual acuity of 20/40 or better for near and distant vision, which is an important aspect of biological science research. Thus, candidates can still pursue their dream of becoming an astronaut if they fall within these predefined limits.

Corrected Visual Acuity

Corrected visual acuity refers to the clarity of vision achieved using corrective lenses, including glasses, contact lenses, or eye surgeries. To be eligible for an astronaut candidate position, both distant and near visual acuity must be correctable to 20/20 in each eye. This ensures that astronauts can effectively operate jet aircraft and perform other crucial tasks during missions.

Evaluating visual acuity is the procedure for determining if an astronaut candidate requires glasses, contact lenses, or eye surgeries. It is acceptable for the candidate to have their eyesight corrected to 20/20 using glasses or LASIK eye surgery. Provided the candidates meet these requirements, they can start their progression towards becoming an astronaut.

Vision Correction Options for Aspiring Astronauts

Astronaut candidates wearing corrective lenses

The good news is that aspiring astronauts have various vision correction options to help them meet the vision requirements set by space agencies. These options include:

  • PRK
  • Contact lenses
  • Glasses

These options are designed to improve visual acuity and ensure the safety and success of space missions, including those on the International Space Station.

We will now examine these vision correction options in more detail and learn how they can help meet the visual acuity standards needed for a successful career in space.

LASIK and PRK Eye Surgeries

Both LASIK and PRK eye surgeries are refractive surgical procedures to correct vision deficiencies and enhance visual acuity. NASA endorses these surgical procedures for astronaut candidates, provided the surgical procedure is performed at least one year before the application. These procedures are considered stable and safe for potential astronauts, with no known adverse effects that would prevent acceptance.

LASIK surgery, for example, improves visual acuity by altering the shape of the cornea to facilitate how light reaches the retina. This enhances vision, with approximately 99% of people achieving uncorrected vision of 20/40 or better after LASIK surgery.

Choosing LASIK or PRK surgeries can notably enhance the probability of meeting the visual acuity requirements for astronaut candidates.

Contact Lenses and Glasses

For those who may not be eligible or prefer not to undergo eye surgeries, contact lenses and glasses are also acceptable options for astronaut candidates. If the candidates’ vision in both eyes is correctable to 20/20, they can still be considered for the astronaut program.

Many astronauts have worn glasses or contact lenses during their space missions, proving that vision correction aids do not hinder their ability to excel in space exploration. By exploring different vision correction options, aspiring astronauts can ensure that their visual acuity meets the necessary standards for a successful space career.

The Role of Vision in Space Exploration

Astronaut in space station with Earth in the background

Vision plays an indispensable role in space exploration, as astronauts face unique visual challenges in microgravity environments and require high visual acuity for mission success. The ability to accurately interpret and perceive visual information in a dynamic and rapidly changing environment is crucial for navigating and operating spacecraft, conducting experiments, and identifying potential hazards or anomalies. In this context, computer science and physical science play significant roles in developing tools and systems that aid astronauts in maintaining their visual acuity.

In this part, we will review the visual challenges astronauts face in microgravity and discuss the significance of visual acuity for the success of space missions.

Visual Challenges in Microgravity

Microgravity environments can cause various visual changes and challenges for astronauts. One such condition is Space-Associated Neuro-Ocular Syndrome (SANS) or Visual Impairment Intracranial Pressure Syndrome (VIIP), which encompasses swelling of the optic nerve, alteration in the shape of the eye, and visual impairment.

These visual challenges can significantly impact astronauts’ safety and performance in space. For instance, decreased visual acuity can affect their ability to execute tasks that require precise visual perception and coordination. As a result, addressing these challenges and maintaining optimal vision become imperative for astronauts during their missions.

Importance of Visual Acuity for Mission Success

High visual acuity is vital for astronauts to perform complex tasks, operate equipment, and ensure the success of space missions. It enables them to interpret and perceive visual information accurately in a dynamic and rapidly changing environment. Moreover, maintaining high visual acuity allows astronauts to monitor their health and detect any changes or abnormalities in their vision that may occur during spaceflight.

The potential implications of poor visual acuity on the success of a space mission can be severe. For example, astronauts may experience a decline in visual acuity after returning from space missions, which can affect their overall well-being and future mission assignments. Hence, astronauts need to maintain optimal vision and eye health to ensure a successful mission.

Astronaut Training and Vision Tests

Astronaut candidates in astronaut training

Astronaut candidates undergo stringent vision testing during the astronaut candidate program selection process to confirm they meet the necessary visual acuity requirements. These tests include visual acuity, colour vision, and examination of the extraocular muscles, all crucial in assessing the astronaut’s ocular health and ensuring their capability to perform tasks during space missions.

In addition to the selection process, astronauts continue to receive ongoing vision assessments throughout their careers. Regular assessments help monitor their visual health and ensure they maintain the required standards for safe and successful space missions.

Vision Testing During Selection Process

During the astronaut selection process, candidates undergo comprehensive vision tests to meet the necessary visual acuity requirements. These tests assess various aspects of the astronaut’s ocular health, such as visual acuity, colour vision, and extraocular muscle examination.

The exact visual acuity requirements vary depending on the position. For example, pilot astronauts must have a minimum 20/50 uncorrected vision, correctable to 20/20 vision, while mission specialist candidates must possess 20/200 or better-uncorrected vision. Meeting these requirements enables astronaut candidates to progress in the selection process and follow their dreams of space exploration.

Ongoing Vision Assessments

Astronauts receive regular vision assessments to monitor their visual health and ensure they maintain the required standards for space missions. These assessments include tests for:

  • Visual acuity
  • Color vision
  • Extraocular muscles
  • Ocular health

The frequency of these assessments may vary, but they are typically conducted before, during, and following space missions to monitor any alterations in astronauts’ vision.

In addition to the standard vision tests, astronauts undergo specific assessments, such as visual acuity, contrast sensitivity, and visual field testing, to evaluate their overall visual function. These ongoing assessments play an essential role in understanding and mitigating the changes to the human eye induced by microgravity that astronauts may face during their missions.

Real-life Examples of Astronauts with Vision Correction

Astronauts in space suits during spacewalk

Becoming an astronaut is not reserved for those with perfect vision. Real-life examples of astronauts who have undergone vision correction procedures, such as LASIK or PRK, showcase that less-than-perfect vision does not preclude a successful space career. These astronauts have overcome visual challenges and demonstrated exceptional performance in space exploration.

Examples include NASA astronauts who have worn glasses or contact lenses during their missions, proving that vision correction aids do not hinder their ability to excel in space exploration. Whether undergoing vision correction procedures or using vision correction aids, aspiring astronauts can chase their dreams of exploring the cosmos, irrespective of their initial visual acuity.

Tips for Aspiring Astronauts with Less Than Perfect Vision

If you’re an aspiring astronaut with less-than-perfect vision, don’t let that stop you from pursuing your dream. By exploring available vision correction options and focusing on meeting NASA’s visual acuity requirements, you can overcome visual challenges and take your place among the stars.

Consider evaluating the possibility of LASIK surgery, investigating vision training, and verifying correctable vision. Taking these steps will enable you to improve your visual acuity and guarantee that you meet the required standards for a successful career in space. If LASIK surgery is not an option, you may need to wear corrective lenses to achieve the necessary visual acuity.

Remember, the sky isn’t the limit; it’s the starting point and the final consideration in our journey to greatness!


In conclusion, having a less-than-perfect vision should not deter you from pursuing a career as an astronaut. By understanding the vision requirements for astronaut candidates, exploring available vision correction options, and appreciating the importance of visual acuity in space exploration, you can navigate the path to a successful space career.

Whether you choose LASIK, PRK, contact lenses, or glasses, the key is to meet the necessary visual acuity requirements and maintain optimal vision and eye health throughout your astronaut journey. So, dream big, aim high, and let your vision propel you towards the stars!

Frequently Asked Questions

Can you be an astronaut with bad eyesight?

You can be an astronaut with bad eyesight if you have 20/20 vision or better with corrective lenses. Approximately 80% of astronauts wear glasses or contact lenses to achieve this requirement.

What disqualifies you from being an astronaut?

Having a vision that can’t be corrected to at least 20/20, too high blood pressure, or being outside of the height range of 58.5-76 inches can disqualify you from being an astronaut through NASA. Additionally, having any medical conditions that impair one’s ability to participate in spaceflight will also make you ineligible.

What is the perfect eyesight for astronauts?

Astronauts must have vision correctable to 20/20, which can be achieved through glasses. Apollo veteran John Young even took his reading glasses with him on a mission, and two astronauts tried out a new type of spectacles called Superfocus lenses in STS-133. All astronaut candidates must pass the NASA long-duration astronaut physical with 20/20 vision or better.

Can I be an astronaut with one eye?

Although there are vision requirements to become an astronaut, the applicants with physical disabilities vacancy do not need to have visual acuity in both eyes of 100% (20/20). Astronaut pilots also cannot be colorblind. Therefore, it is possible to be an astronaut with one eye.

Are LASIK and PRK eye surgeries allowed for astronaut applicants?

Yes, astronaut applicants are allowed for LASIK and PRK eye surgeries, provided they meet the appropriate criteria and do not have any long-term complications.


  1. NASA. (2022, January 15). Astronaut candidate program. https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Astronaut_Candidate_Program.html
  2. Space Foundation. (2020, May 18). Vision requirements for astronauts. https://www.spacefoundation.org/2020/05/18/vision-requirements-for-astronauts/
  3. Vision requirements for astronauts. (n.d.). Space Camp. https://spacecamp.com/blog/vision-requirements-for-astronauts
  4. Gorn, M. (2017, August 3). Do astronauts need perfect vision? Scientific American. https://www.scientificamerican.com/article/do-astronauts-need-perfect-vision/
  5. Vision requirements for astronauts. (2022, January 15). NASA. https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Astronaut_Candidate_Program.html
  6. NASA. (2021, May 13). What are the vision requirements to become an astronaut? https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Astronaut_Candidate_Program.html
  7. Vision requirements to become an astronaut. (2020, January 15). Space Center Houston. https://spacecenter.org/vision-requirements-to-become-an-astronaut/
  8. Vision requirements for astronauts. (2019, January 15). Space Foundation. https://www.spacefoundation.org/2019/01/15/vision-requirements-for-astronauts/
  9. Johnson, W. (2018, May 3). Can you become an astronaut if you need glasses? The Balance Careers. https://www.thebalancecareers.com/can-you-become-an-astronaut-if-you-need-glasses-4145483
  10. NASA. (2016, March 15). Vision requirements and medical standards for astronauts. https://www.nasa.gov/audience/foreducators/postsecondary/features/F_Vision_Requirements.html


Photo graph of Dr. Conlon operating with loops on.

Dr. M. Ronan Conlon started his career in the field of ophthalmology at the same time as the development of refractive eye surgery in Canada. In 1996, he brought laser technology to Canada from Germany, which allowed him to perform laser eye surgery before it was available in the United States. With the establishment of the Conlon Eye Institute, Dr. Conlon has performed more than 40,000 refractive procedures and has advanced his expertise in LASIK and refractive cataract surgery.


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