Comment on: “Polymer Co-Coating of Gold Nanoparticles Enables Their Integration Into Contact Lenses for Stable, Selective Ocular Light Filters”

We recently read an article published in Advanced Materials Interfaces, “Polymer Co-Coating of Gold Nanoparticles Enables Their Integration Into Contact Lenses for Stable, Selective Ocular Light Filters,” by Clasky et al., 2022. We found that article to be of considerable interest. This new technology for tuning the spectral filtering properties of contact lenses is intriguing and might indeed be developed into anti-myopia therapies. However, we feel that the statement “Chronic exposure to long-wavelength (red) light is associated with increased incidence and progression of myopia in preclinical models” ignores important inter-species differences in the response to removing red light and may mislead readers into thinking that filtering out long wavelength (red) light will slow myopia in children. In fact, the current evidence from primate and close-to-primate animal models strongly suggests the opposite: that it is blocking short wavelength light (less than 500nm) that has anti-myopic properties.

In some species, red light exposure promotes myopia (chickens ^[1] guinea pigs ^[2] and fish ^[3]) and is consistent with the authors’ suggestion that blocking red light might be anti-myopiagenic. However, exposure to long wavelength red light produces a powerful and consistent anti-myopia effect in both the rhesus monkey ^[4] and the closely-related diurnal tree shrew ^[5]. More recently, it was shown that amber light, spanning a relatively broad band of frequencies but omitting those shorter than 500 nm, also promotes hyperopia in tree shrews ^[6]. Although the reason for the inter-species differences is not yet known, the data from animals close to humans suggest that blocking the blue, rather than the red wavelengths, is more likely to prevent myopia progression.