Space exposure reveals new insights into intraocular lens material stability

Understanding how implantable devices behave beyond Earth is becoming increasingly relevant as long-duration spaceflight moves closer to reality. Data from the International Space Station offer a unique opportunity to assess how intraocular lens materials respond to extreme environmental stressors such as radiation, ultraviolet exposure and vacuum conditions.

At ASCRS 2026, Dr Morgan Micheletti (Berkeley Eye Center, Houston, Texas) and colleagues were awarded Best in Session for their abstract on findings from the JAMES study, exploring structural and optical changes across a range of commonly used IOL designs. In this Q&A, he discusses the study rationale, key observations and the implications for future device handling, storage and potential surgical use in spaceflight.

Abstract information: Joint Assessment of Materials Exposure in Space (JAMES): IOL Changes after Direct Exposure to Space Aboard the International Space Station. Abstract authors: Dr. Morgan Micheletti, MD, FACS, ABO; Liliana Werner, MD, PhD. Presented at ASCRS 2026, Washington D.C., 10-13 April 2026.

What drove the selection of IOL materials and designs included in this study?

The goal was to include a broad, clinically relevant cross-section of intraocular lens materials and designs currently used in cataract and refractive lens surgery. We wanted to study not just one lens platform, but the major material categories ophthalmologists rely on today, including hydrophobic acrylic, hydrophilic acrylic, silicone, and collamer-based lenses, as well as a range of modern optical designs such as monofocal, toric, extended depth-of-focus, multifocal/trifocal, light-adjustable, and phakic implantable collamer lenses.

This diversity was important because the JAMES mission was designed as an early step toward understanding how surgical implant materials may tolerate transport, storage, and potential use during long-duration spaceflight. By exposing representative IOL materials to different external ISS environments—Ram-facing high atomic oxygen exposure, Zenith-facing high ultraviolet exposure, and an underdeck partially shielded environment—we could begin to identify whether certain materials or designs appear more vulnerable to specific space-environment stressors.

What were the most important material or optical changes observed after space exposure?

The most notable changes were concentrated in lenses that were closest to direct exposure. Several Ram-facing lenses demonstrated optic cracks, localized opacification, and surface roughening, sometimes with an appearance similar to localized “burns.” These findings were most prominent in tray 1, the tray closest to the exposure window.

We also observed yellow optic discoloration in several lenses, particularly after Zenith exposure and in one Ram-exposed silicone lens. Spectrophotometry showed that these discolored lenses had reduced light transmission, especially in the blue-violet range of the visible spectrum, which is clinically relevant because changes in transmission could potentially affect optical performance.

A third important finding involved the light adjustable lenses. The exposed light adjustable lenses, both with and without ActivShield, showed diffuse optic opacification and a distinctive surface change on microscopy and SEM, described as having a “cobblestone” or “bubble-wrap” appearance. This was notable because similar changes were seen across Ram, Zenith, and underdeck locations, suggesting that some materials may be sensitive not only to the most direct exposure conditions but also to broader external ISS environmental factors such as vacuum, temperature cycling, and ambient radiation.

It is important to emphasize that these lenses were removed from their original packaging and deliberately subjected to extreme, unprotected conditions. The study should not be interpreted as suggesting that currently packaged IOLs are unsafe for terrestrial clinical use. Rather, it highlights how much we still need to learn about medical-device handling and protection in space.

What are the key implications of these findings for IOL storage, transport and future surgical use in spaceflight?

The key implication is that we cannot assume that implantable medical devices will behave the same way in space as they do on Earth. IOLs are designed, packaged, sterilized, stored, and transported for terrestrial conditions. For future lunar habitats, Mars missions, or long-duration exploration-class missions, we will need to understand how packaging, shielding, transport conditions, and storage environments affect the integrity of implantable devices.

For ophthalmology specifically, this matters because cataract surgery is one of the most common surgical procedures on Earth, and cataract formation is a foreseeable issue for aging crews and long-duration space travelers. If humans are going to live and work off-planet for extended periods, we need to know whether IOLs can be safely transported, stored, and ultimately used in those environments.

The JAMES mission provides an early framework for that work. It suggests that future studies should evaluate protective packaging, shielding strategies, sterilization and storage methods, and perhaps material-specific recommendations for spaceflight. More broadly, it opens the door to a new area of collaboration between ophthalmology, materials science, and space medicine.