Solar Full-Spectrum Radiation vs Indoor LED Spikes: Longitudinal Chromatic Aberration & Scleral Glycosaminoglycans

The human eye has approximately $1.25\ \text{Diopters}$ of Longitudinal Chromatic Aberration across the visible spectrum:

$$F(\lambda = 420\ \text{nm}) - F(\lambda = 650\ \text{nm}) \approx \mathbf{+1.25\ \text{Diopters (Chromatic Spread)}}$$

Under full-spectrum sunlight, short blue wavelengths focus ahead of the retina (myopic defocus), while long red wavelengths focus behind (hyperopic defocus). The retina compares the contrast ratio of S-cones to L-cones to determine whether the eye is growing too long or too short.

Modern white LEDs lack short violet ($380\text{--}410\ \text{nm}$) and deep red ($650\text{--}780\ \text{nm}$) wavelengths. Lacking these chromatic bookends, the retina's emmetropization sensor cannot detect the sign of defocus, defaulting into an error state that signals the sclera to continuously elongate.

Under indoor light deprivation, posterior scleral fibroblasts downregulate the synthesis of sulfated Glycosaminoglycans (GAGs), including aggrecan and decorin. The scleral matrix loses water-binding capacity, thinning by over $30\%$ at the posterior pole and stretching outward into high pathological myopia.