blue-light-filtering lens

A blue-light-filtering lens is a spectacle lens that absorbs or reflects ultraviolet radiation and part of the short-wavelength, blue end of visible light.¹ Most versions look nearly clear, and the measured curve of one common lens passes almost all visible light while cutting part of the band below about 430 nm.²

These lenses are sold to relieve eye strain from screens, to improve sleep and to protect the macula. A review of 17 randomized trials found that they may not reduce eye strain from computer use over the short term and probably do not change visual acuity.¹ Their effect on sleep was uncertain because the trials disagreed, and no trial measured macular health.¹

Screen discomfort is better explained by reduced blinking, which dries the ocular surface, and the American Academy of Ophthalmology does not recommend blue-light-blocking eyewear for computer use.³ A near-clear blue-light lens differs from the amber long-pass filters used in low vision, which absorb nearly all light below about 500 nm.²