Anti-glare or anti-reflective lens coatings and blue cut lenses are helpful for reducing two of the most common causes of eyestrain. Depending on when you wear glasses, you may prefer lenses that reduce the amount of reflected light that reaches your eyes or lenses that have coatings or substrates that filter out a significant amount of blue light. Here are three essential distinctions between anti-glare lenses and anti blue light glasses.
1. Anti-Glare or Anti-Reflective Lenses Improve Clarity
Anti-reflective lens coating is intended to prevent back-glare, which occurs when light strikes the back of glasses lenses and is reflected into your eyes. Anti-glare lenses work by equalizing the intensity of light that is reflected from the inner and outer surfaces of the film by producing destructive interference. This hard, thin film has a thickness of about a quarter of the wavelength of light and an index of refraction between air and glass.
Lens coatings that are designed to reduce glare or reflection permit the full spectrum of visible light to pass through, including blue light. Lenses with this type of coating are designed primarily to improve clarity of vision that could otherwise be diminished by glare, which is most useful for reducing eye strain and enhancing vision. Glasses with anti-reflective lens coatings may be ideal for several activities, from screen use to night driving.
2. Blue Cut Lenses Block Blue Light
Blue cut lenses are designed to absorb anywhere from 10% to over 90% of blue light. Blue light is visible light with high energy in the range of 380 nanometers to 495 nanometers. This type of lens is designed to allow some blue light to pass through to prevent color distortion. The amount of color distortion may increase with lenses that are designed to block more than 50% or 60% of blue light from passing through to your eyes.
Anti blue light glasses can immediately reduce symptoms of digital eye strain, especially when working at night. Over time, wearing blue blockers while working on digital devices may help to normalize your circadian rhythm and risk of macular degeneration.
3. Lenses May Be Coated or Infused
Anti-reflective lenses almost always have a hard coating on both sides of the lens. This coating is most necessary for lens materials that have a high index of refraction, as these lenses reflect more light than plastic lenses.
Blue cut lenses may feature layered substrates or blue light blocking coatings, depending on the brand. Some blue light-blocking lenses are infused with melanin, which filters out up to 98% of blue light. Progressive glasses made with this substance, which naturally occurs in skin, may have a brownish-yellow tint.
Depending on whether optic clarity or color accuracy is the deciding factor, you may prefer to order glasses with either anti-glare or blue cut lenses. Choose lenses with an anti-reflective coating if you want to see more clearly and reduce eye strain. If blocking more of the blue light that emanates from backlit digital devices is your top priority, anti blue light glasses are the best choice.