Ocular trauma or other ocular conditions can be significantly debilitating in space. A literature review of over 100 articles and NASA evidence books, queried for eye related trauma, conditions, and exposures was conducted. Ocular trauma and conditions during NASA space missions during the Space Shuttle Program and ISS through Expedition 13 in 2006 were reviewed. There were 70 corneal abrasions, 4 dry eyes, 4 eye debris, 5 complaints of ocular irritation, 6 chemical burns, and 5 ocular infections noted. Unique exposures on spaceflight, such as foreign bodies, including celestial dust, which may infiltrate the habitat and contact the ocular surface, as well as chemical and thermal injuries due to prolonged CO2 and heat exposure were reported. Diagnostic modalities used to evaluate the above conditions in space flight include vision questionnaires, visual acuity and Amsler grid testing, fundoscopy, orbital ultrasound, and ocular coherence tomography. Several types of ocular injuries and conditions, mostly affecting the anterior segment, are reported. Further research is necessary to understand the greatest ocular risks that astronauts face and how better we can prevent, but also diagnose and treat these conditions in space. 3205 npjmicrogr NPJ Microgravity NPJ Microgravity Nature Publishing Group PMC10188687 10188687 10188687 37193709 10.1038/s41526-023-00279-y Ocular conditions and injuries, detection and management in spaceflight Meer Elana 1 2 Grob Seanna 1 Antonsen Erik L 3 Sawyer Aenor 2 4 ✉ 1 Department of Ophthalmology, University of California San Francisco, San Francisco, CA USA 2 University of California Space Health Program, San Francisco, CA USA 3 Department of Emergency Medicine and Center for Space Medicine, Baylor College of Medicine, Houstan, Texas USA 4 Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA USA ✉ Corresponding author. Characterization of ocular injuries and conditions in space The Exploration Medical Conditions List at NASA has been the source of medical conditions considered for probabilistic risk analysis regarding medical risk in the past 10 . This list has historically included four eye specific conditions: Eye Chemical Burn, Eye Corneal Ulcer, Eye Infection, and Retinal Detachment. In one assessment, Eye Chemical Burn was the top influential medical condition contributing to the probability of evacuation for certain ISS mission conditions 10 . Table 1 Medical condition and symptomatology during NASA Space Missions Obtained from Lifetime Surveillance of Astronaut Health (LSAH) records for medical conditions that occurred among US astronauts during the Space Shuttle Program and ISS through Expedition 13 in 2006. Medical Condition/Symptoms Number of Events Eye Abnormality unspecified 9 Eye Debris 4 Dry Eyes 4 Eye Irritation 5 Puffy eyes 1 Eye Abrasion (Foreign Body) 70 Eye Chemical Burn 6 Eye Infection 5 Data derived extracted from NASA Evidence books 4 . On a macroscopic level, choroidal folds, cephalad fluid shifts and edema, and globe flattening have been described in the literature, as well as a multitude of microscopic effects due to a combination of microgravity and environmental stressors 36 . Space flight elicits gene expression and histologic changes by inducing oxidative and cellular stress responses in the mouse retina affecting the expression of multiple genes responsible for triggering a protective response 33 , 37 , 53 – 56 . Exacerbating this predisposition are the many pressure stressors astronauts undergo in the setting of microgravity, pressurized space suits, and high resistance exercise 57 . Persons who are older, have high myopia, history of eye trauma or prior eye surgery, or family history of retinal detachment are also at higher risk for retinal tear in general, unrelated to spaceflight. Diagnosis and treatment Retinal examination to evaluate for retinal tears or other retinal pathology requires a complete dilated fundoscopic examination with scleral depression to visualize peripherally to the ora serrata. On ISS this may be challenging given the lack of equipment and ophthalmologic training. While not classically an “injury,” it is important to discuss as certain key components of the space flight environment may increase the risk of this sight threatening condition. Potential causes of injury and known data on injury in spaceflight As described, there are several metabolic changes underlying changes in the vasculature of the retina 58 . These changes in vessel caliber and density may be compounded by hypercoagulability in space 59 – 61 , increasing the risk for occlusion of the retina, an ophthalmologic emergency. Ocular chemical burn Definition Ocular chemical burns may occur secondary to a corrosive substance being introduced into the eye or periocular tissue. Potential causes of injury and known data on injury in spaceflight Prolonged Co2 exposure in space flight may lead to ocular toxicity 64 . This is exacerbated by the reduced air convection in microgravity leading to local pockets of C02 developing around the nose and mouth and facial area 57 . In probabilistic analysis of medical risks, eye chemical burn and burns secondary to fire are the most likely environmental causes of medical illness leading to evacuation on ISS to earth 10 . As needs for crew autonomy increase with distance from Earth, strategies must be developed to ensure that the acute response to ocular medical issues will be as robust as possible. Protective/preventative measures Given the potential for considerable short-term symptoms and long-term effects of ocular injury in space, preventative measures have been the cornerstone of medical care for astronauts to date. Protective eyewear (Goggles) The emergency eyewash system design includes a pair of swim goggles and tubing to allow for high flow water eyewash delivery. During EVAs, crew members wear two-piece semi-rigid spacesuits.