New Myopia Theory: Close-Up Focus in Low Light May Drive Nearsightedness

New research from scientists at the SUNY College of Optometry suggests that myopia, or nearsightedness, may be primarily driven by prolonged close-up focus in low-light indoor environments. This behavior is proposed to limit the amount of light reaching the retina, offering an alternative or complementary explanation to increased screen time for the condition's rising rates.

Myopia's Global Rise

Myopia has reached significant levels globally, affecting approximately 50% of young adults in the United States and Europe, and nearly 90% in parts of East Asia. While genetics contribute to an individual's risk, the rapid increase observed over recent generations indicates that environmental factors play a critical role. Researchers propose a unifying neuronal mechanism aimed at reconciling various factors previously linked to myopia induction and control.

Proposed Mechanism: Retinal Illumination and Pupil Response

The study's central hypothesis focuses on how light exposure to the retina is influenced by both ambient light levels and the eye's focusing actions.

In bright outdoor light, the pupil naturally constricts for protection, yet allows ample light to reach the retina.
When individuals focus on close objects indoors, such as phones or books, the pupil constricts to sharpen the image.
The research suggests that in dim indoor lighting, the combined effect of close-up focusing and low ambient light can significantly reduce the amount of light reaching the retina.
According to this mechanism, myopia may develop when insufficient retinal illumination fails to generate robust retinal activity, often due to dim light sources and excessive pupil constriction at short viewing distances.

Conversely, the hypothesis predicts that myopia may not develop when the eye is exposed to bright light, and pupil constriction is regulated by image brightness rather than solely by viewing distance.

Accommodation and Negative Lens Impact

The research also found that negative lenses, commonly used to correct myopia, can reduce retinal illumination by causing pupil constriction through accommodation—the eye's adjustment to focus at short distances.

This pupil constriction intensifies with shorter viewing distances, stronger negative lenses, and sustained accommodation.
The effect becomes more pronounced as the eye develops myopia.
Disruptions in eye turning during accommodation and reduced effectiveness of blinks in influencing pupil constriction were also observed in myopic eyes.

Implications for Myopia Management

If validated, this mechanism could inform future strategies for understanding and managing myopia. It suggests that control of the condition may involve exposing the eye to safe levels of bright light while simultaneously limiting accommodative pupil constriction. This reduction in constriction can potentially be achieved through:

Reducing accommodative demand with specific types of lenses, such as multifocal or contrast-reduction lenses.
Using pharmacological agents, such as atropine drops, to block the muscles responsible for pupil constriction.
Increasing time spent outdoors, particularly focusing on distant viewing without engaging near accommodation.

The mechanism further predicts that current myopia control strategies may be less effective if individuals continue prolonged, excessive accommodation indoors under low light conditions.

Study Details

The research was conducted by Urusha Maharjan, a doctoral student, and collaborators in Jose-Manuel Alonso's laboratories at the SUNY College of Optometry, with Jose-Manuel Alonso serving as the senior author. The findings are scheduled for publication in Cell Reports on February 17, 2026. Researchers emphasize that this is a testable hypothesis requiring further investigation.