Testing a novel emmetropization mechanism model based on opponent spectral/spatial information in young children

The National Eye Institute awarded The New England College of Optometry $371,997 on June 1, 2026, under the Vision Research program (CFDA 93.867) to test a novel emmetropization mechanism model based on spectral and spatial opponent information in young children with myopia.

The project will investigate how the retina controls eye growth and refraction through a blue-versus-yellow spectral-opponent mechanism. The research tests whether imbalances in retinal spectral and spatial information—specifically the contrast between short and long wavelengths and low and high spatial frequencies—drive changes in choroid thickness and axial length in emmetropic children. The study posits that outdoor environments, which contain high light levels and wide ranges of wavelengths and spatial frequencies, may protect against myopia development by maintaining balance in this opponent mechanism. The work will measure choroid thickness and axial length immediately before and after exposure to different spectral and spatial combinations.

Performance occurs in Boston, Massachusetts, with work running through May 31, 2028. This is a Project Grant, a competitive, peer-reviewed mechanism within the Vision Research program focused on innovative research to understand the eye and visual system and prevent vision diseases.

Abstract

Myopia is a common childhood condition that typically develops when the normal emmetropization mechanism fails, and is considered the biggest eye threat of the century due to its increasing prevalence and associated risk for blindness. To prevent or efficiently treat myopia, its etiology must be first understood. Children spending more time outdoors are less likely to develop myopia (or develop IT later), but the specific outdoor attributes protecting against myopia are not fully known. Outdoor scenes have high light levels and a wide range of wavelengths and spatial frequencies (SFS). Insights into how the retina controls emmetropization in the grow- ING eye will guide future longitudinal studies of the visual environment's influence on the incidence of myopia. Our application will test a new retinal emmetropization model based upon the spectral-opponent blue VS. YEL- low (B-Y) mechanism. The B-Y receptive field center is comprised of an S-cone surrounded by L- and M-cones. In our model, the S-cone is also a low-pass spatial filter in opposition to the L/M-cone high-pass filter. Thus, the receptive field center is both spectrally and spatially opponent to its surround. When retinal spectral/spatial in- formation stimulates the center/surround equally, the B-Y mechanism is balanced and does not change the AX- IAL length (AXL). When imbalanced, either spectrally or spatially, the BI-directional mechanism changes choroid thickness (CHT), lengthening or shortening AXL to balance the B-Y response. To do so, the proposed mecha- nism needs a retinal image containing wide ranges of SF and visible wavelengths, similar to outdoor scenes. We propose to test the model for different spectral (short and long wavelengths) and spatial (contrast of low and high SFS) combinations. CHT and AXL will be measured immediately before and after young emmetropic children (5-10 years) with normal vision view the different gratings. In aim 1, we will assess the impact of differ- ENT combinations of spectral/spatial information on these biomarkers. We will determine (a) the balance point for spectral/spatial image content that does not induce CHT/AXL changes, and (B) whether and how much spectral information is more or less important than spatial information for inducing the changes. Outdoor light levels are higher than those commonly found indoors in schools. In aim 2 we will assess how different retinal flux densities affect CHT/AXL. Three spatial/spectral images will be presented to subjects at two light levels: (a) one image will be dominated by long-wavelengths/high spatial frequencies, hypothetically increasing CHT/DE- creasing AXL, (B) one will be dominated by short-wavelengths/low spatial frequencies, hypothetically decreas- ING CHT/increasing AXL, and (C) one will be neutral with no expected CHT/AXL changes. We will use a ten-fold range of light levels to test responses at levels ranging from indoor levels to those experienced outdoors. The proposed studies will test our novel emmetropization model and provide important insights into the way the retina's mechanism responds to environmental stimuli. The results of these studies will form a foundation for long-term studies on how indoor environments should be designed to limit myopia development in children.