The Science Behind How Protective Lenses Shield Your Eyes From Harmful Rays

Like your skin, your eyes are vulnerable to harmful UV rays. Wearing tinted sunglasses with UV protection is essential during sunny days.

Plastic photochromic lenses contain carbon-based compounds with scary-sounding chemical names. When exposed to UV light, these molecules change shape, becoming darker as they absorb more visible light.

Ultraviolet (UV) Rays

Many people know the sun’s UV rays harm your skin, but fewer realize that long-term exposure can damage eyes and vision. UV rays are invisible electromagnetic radiation that appears on the electromagnetic spectrum between visible light and X-rays. They are split into three categories: UVA, UVB, and UVC.

UV rays radiate from the sun and can be reflected from water, snow, sand, and other bright surfaces. They are most dangerous when the sun is at its peak, typically from 10 a.m. to 2 p.m.

Many eye conditions are associated with excessive UV exposure, including photokeratitis and photo conjunctivitis. While these conditions are usually temporary, they can be painful. Repeated exposure to UV rays increases your risk of developing macular degeneration, leading to permanent central vision loss. It also can cause cataracts, a clouding of the lens that reduces vision and can lead to blindness.

Blue Light

Many people are concerned about the effect of blue light from backlit digital screens on their eyes. This light has a shorter wavelength than other colors in the visible spectrum, and it can cause eye strain due to its ability to scatter within the cornea and lens. This scattered light makes it challenging to focus and can result in glare on the screen.

Fortunately, the structures in our eyes that protect us from UV rays also effectively block blue light from reaching the retina in the back of our eyes. Our retinal specialists are frequently asked if this light increases our risk of age-related macular degeneration and other forms of blindness.

Our retinal specialists recommend yellow-tinted filters available for most electronic devices to decrease the blue light they emit. Computer glasses with yellow-tinted lenses and anti-reflective lens coatings can also help reduce eye strain by blocking blue light and increasing the contrast.

Infrared (IR) Rays

Like visible light, IR travels across the electromagnetic spectrum but has longer wavelengths and lower energy. The human skin can detect it as heat, but only certain organisms—such as mosquitoes, vampire bats, and some snake and bed bug species—can see it.

When exposed to IR, the eye can suffer damage similar to UV exposure. This is because the IR energy passes through the cornea and lens, raising their internal temperature. This thermal effect can damage the lens, leading to cataracts.

To protect against this, many safety glasses like dream lens Halifax will help your eyes or goggles adorned with orange or green tints block out harmful IR. Alternatively, full-face shields can be worn to provide complete protection against IR rays. In addition, some workers may use IR-absorbing coatings or lenses on their work helmets. 


Workplace hazards can cause eye injury if the protective gear is not worn correctly or maintained. This includes splashes, sprays, or vapors of chemicals that could be harmful to your eyes, especially when they come in contact with a hard surface like the cornea. Ensure your employees know that goggles should be used under a face shield to protect their eyes from chemicals.

Virtually every activity creates dust particles that could be hazardous to your eyes. Yardwork, woodworking, and construction are just a few everyday situations that create eye-hazardous dust particles.

The irritation can last days when these foreign particles are caught in the eye. Attempting to rub them out can scratch the cornea, leading to permanent damage requiring medical attention. That’s why it’s essential to use anti-fog protective lenses – otherwise, those annoying dust particles can keep coming back into the eye. This is also why protective lenses must be replaced when pitted, scratched, or damaged.

Richard Brown


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.