Summary: The worldwide rise in myopia (nearsightedness) is commonly blamed on screen use, but new research from the SUNY College of Optometry points to a physiological explanation: insufficient retinal illumination during prolonged near work in low indoor light. The investigators propose that sustained close-up focus causes pupil constriction (via accommodation), which, when combined with dim lighting, reduces the light reaching the retina and may drive myopia development.
When people read, study, or use devices indoors under low lighting, their pupils constrict to sharpen the image. In those conditions the retina receives far less stimulation than it does outdoors, where bright light and distant viewing keep the retina well illuminated. This “light starvation” hypothesis offers a single mechanism that can help explain why outdoor time protects against myopia and why interventions that increase retinal illumination or reduce accommodative pupil constriction—such as atropine drops, multifocal lenses, or spending time outdoors—can slow myopia progression.
Key Facts
- Light starvation hypothesis: Myopia may result from too little light reaching the retina due to the combination of dim indoor lighting and pupil constriction during near work.
- Pupil constriction during accommodation: Focusing on close objects triggers pupil constriction primarily to improve image sharpness. In low light, this further limits retinal activity.
- Sustained near work intensifies the effect: Prolonged accommodation, especially over tens of minutes, increases pupil constriction and reduces retinal stimulation—an effect that is stronger in individuals who are already myopic.
- Explains diverse treatments: The mechanism unifies why outdoor light, atropine (which dilates the pupil), multifocal lenses (which lessen accommodative demand), and reduced contrast strategies can all help control myopia.
- Widespread impact: Myopia now affects a large portion of young adults globally, with rates approaching 50% in parts of the U.S. and Europe and substantially higher percentages in several East Asian regions.
Source: SUNY College of Optometry
Background
Rising myopia rates have long been associated with increased near work and screen exposure, particularly among children and young adults. The SUNY study, published in Cell Reports, refines that view by identifying a physiological pathway: near work performed in dim indoor light reduces retinal illumination via accommodative pupil constriction, weakening retinal activity that is important for normal eye growth.
Jose-Manuel Alonso, MD, PhD, SUNY Distinguished Professor and senior author, notes the global scale of the problem: myopia blurs distance vision and has become highly prevalent worldwide, with strong evidence that environmental factors—especially visual habits and lighting—play a major role alongside genetics.
In animal models, myopia can be induced by visual deprivation or negative lenses; these approaches engage different neuronal pathways. Clinically, multiple interventions—multifocal lenses, atropine eye drops, contrast reduction, and promoting outdoor time—have proven effective to varying degrees. SUNY researchers propose a unifying neuronal mechanism that explains how these apparently different methods influence myopia progression.
Urusha Maharjan, a doctoral student at SUNY Optometry and lead researcher on the study, explains: in bright outdoor light the pupil narrows in response to brightness but the retina still receives abundant light. Indoors, however, focusing close-up causes pupil constriction for image sharpening rather than as a response to brightness. In dim settings this dual constriction severely limits retinal illumination.
The study shows that negative lenses and short viewing distances increase accommodation, which intensifies pupil constriction and reduces retinal light. Prolonged accommodation strengthens this effect further, and individuals who are already myopic exhibit even greater accommodative pupil constriction. The researchers also observed that accommodation-related eye turning and blink responses may be altered in ways that reduce pupil dilation, further limiting retinal input.
If validated by further research, this model suggests practical prevention and treatment strategies: ensure safe, bright lighting during study or device use; reduce prolonged accommodative demand with multifocal or specially designed lenses; use treatments that limit the pupil-constricting response (for example, atropine); and prioritize outdoor time that combines high ambient light with distance viewing.
The hypothesis also implies a clear warning: any myopia-control approach is likely to fail if the eye remains exposed to excessive near work under low lighting for long periods. Brightening indoor environments and enforcing regular breaks to view distant objects are simple, evidence-aligned measures that may help preserve healthy retinal stimulation.
The study is an early but testable framework that ties together physiological measurements with established epidemiological and clinical findings. Alonso emphasizes that more research is required, but the concept reframes how visual habits, lighting environments, and eye focusing interact in myopia development.
Key Questions Answered:
A: Both matter, but light explains the underlying cause. Screen use often involves near focus in indoor settings that are much dimmer than outdoors. Close-up focus reduces pupil size and, together with low ambient light, deprives the retina of sufficient stimulation to maintain normal eye growth.
A: Outdoor environments provide much brighter light, which ensures the retina receives strong input even when the pupil is small. Outdoor activities also encourage looking at distant objects, reducing sustained accommodation and allowing the pupil to remain more relaxed.
A: Yes—brighter workspaces help. The researchers highlight that prolonged near work under low light is a key risk condition. Adequate lighting, shorter near-work sessions, and periodic distance breaks are practical, science-backed steps to limit myopia progression.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by staff.
About this visual neuroscience research news
Author: Maria O’Brien
Source: SUNY College of Optometry
Contact: Maria O’Brien – SUNY
Image credit: Neuroscience News
Original Research: Open access. “Human accommodative visuomotor function is driven by contrast through ON and OFF pathways and is enhanced in myopia” by Urusha Maharjan, Hamed Rahimi-Nasrabadi, Sabina Poudel, Farzaneh Olianezhad, Jianzhong Jin, Mitchell W. Dul, and Jose-Manuel Alonso. Cell Reports. DOI: 10.1016/j.celrep.2026.116938
Abstract
Human accommodative visuomotor function is driven by contrast through ON and OFF pathways and is enhanced in myopia
The human eye continuously adjusts refractive power, vergence angle, and pupil diameter while exploring the visual environment. Errors in these visuomotor adjustments reduce stimulus contrast that drives the ON and OFF retinal pathways. In refractive disorders such as myopia, ON pathway responses become weaker, slower, and less sensitive.
This study demonstrates that, in addition to sensory deficits, people with myopia have altered visuomotor functions driven by ON and OFF pathways during lens accommodation. Individuals with myopia show excessive accommodative eye vergence, reduced ON pathway dominance, and pronounced accommodative pupil constriction. Excessive pupil constriction could further weaken ON pathway responses and contribute to the pathway deficits observed in myopia.
This mechanism helps account for why activities that maximize accommodative pupil constriction—such as sustained near work in dim light—are associated with increased myopia, while activities and treatments that reduce constriction—such as outdoor exposure, atropine, positive defocus, and low-contrast approaches—are associated with reduced progression.