Ocular toxicity and potential mechanism of nanomaterials: An issue worthy of investigation

Nanomaterials are widely used. The gases emitted from industrial manufacturing contain nanoparticles, which increases the chance of nanomaterials coming into contact with the eyes. Nanomaterials may cause damage to the eyeball wall and eye contents, manifested as keratitis, neovascularization of the iris, vitreous inflammation, retinitis, etc., causing visual impairment. Therefore, the toxicity of nanomaterials to the eyes has received increasing attention, but their specific damage effects and mechanisms have not yet been summarized. In this review, we discuss the impact of nanomaterials on eye damage, the mechanisms, and factors influencing toxicity and look forward to possible solutions. Nanomaterials cause corneal, crystal and vitreous opacity through inflammation, oxidative stress damage and breakdown of calcium homeostasis, leading to eye diseases and impairing light transmission and refraction. When nanoparticles destroy the bloodretinal barrier and further enter the deep retina, direct or indirect damage can lead to the apoptosis of photoreceptor cells and neurons, and the conversion and transmission of light signals can be weakened, ultimately resulting in ocular toxicity. Understanding of these mechanisms will guide further research on the ocular toxicity of nanomaterials and provide ideas for preventing toxicity and developing nontoxic nanomaterials in the future.