Ray approximation

When sunglasses are “polarized,” it means they have a special lens coating that filters certain angles of light. This filtering feature can reduce glare from light reflecting off of surfaces like water or snow. Glare reduction can make certain tasks, like driving, more visually comfortable.

Transmitted ray

The key behind polarized sunglasses lenses is the special chemical that's applied to the lens. The chemical blocks some — but not all — light from entering your eyes.Polarized lenses allow vertical light rays to enter your eyes so it’s possible for you to see correctly. However, horizontal light, as well as light from other angles, is filtered from entering your eyes.By blocking light from other angles, like the light that reflects off snow and water, the lenses significantly reduce glare.Glare reduction often means you’re able to see your point of focus more clearly. It also limits the blinding effect that bright light causes by bouncing off surfaces, as these light waves tend to be horizontal rather than vertical.

While you can benefit from them in most situations, the perks of polarized sunglasses are noticed most in the following settings:

Marginal ray

Polarized sports sunglasses protect your eyes around water by blocking glare reflected off the water's surface. Wraparound sunglasses, along with hats and other sun-shielding apparel, offer even more protection.

From an early age, almost everyone is taught that spending too much time in the sun can be bad for you. While that’s true, the single broad statement has become a kind of scientific boogeyman. Everyone’s wary about the sun, but fewer people know about the importance of UV protection and how it can help preserve your eyes and vision.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Optical throughput

Polarized lenses block glare from smooth road surfaces while driving, especially when roads are wet. Make sure you can read your dashboard and other electronic displays through the lenses!

Sunglasses with a polarized lens coating have unique features that make them a great choice for active people, drivers, and more. Some of these features include glare reduction, UV protection, and more comfortable viewing.

Standard sunglasses are great for reducing overall brightness, but they don’t do much for glare. Polarized sunglasses reduce glare to provide more comfortable vision on particularly bright days.

Research suggests that prolonged exposure to light radiation from the sun without UV protection can increase your risk of developing macular degeneration and cataracts. Macular degeneration is an eye condition that affects your central vision (your ability to see straight ahead). Cataracts — a clouding of the eye’s natural lens — can lead to blurry vision and other symptoms.

Lagrangianinvariantunder transformation

Polarized sunglasses take in vertical light, but filter out horizontal light as well as light from other angles. This effectively blocks out the hazes and glares associated with bright reflections. You'll notice the most difference on sunny days and around reflective surfaces like water and roads. Additionally, polarized sunglasses naturally lessen your need to squint in bright light conditions, which may reduce eye strain and improve visual comfort.

It's a common misconception that you only need UV protection, like sunglasses and SPF, on warm, sunny days. But UV rays reflect extremely well off of cloudy skies, snow, and water. For this reason, it's important to live by the rule of thumb that if it's daytime and you're outside, you should be wearing sunglasses. Doing so can help maintain the health and clarity of your vision.

For $69, you can have a polarized and mirrored tint added to your lenses. This option is especially useful for water sports sunglasses

Ray optical

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

These lenses are useful for hiking trips that will take you to exposed places like mountaintops, particularly in snowy conditions.

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

By subscribing, I confirm that I am over 16 years of age and agree that my personal data can be used by Luxottica Group S.p.A to send me news, special offers, and other marketing communication as part of the Eyebuydirect Loyalty Program. For more information, see our Terms & Conditions, and Privacy Policy.

The Lagrange invariant is a well-known law for optical imaging systems formulated in the frame of ray optics. In this study, we reformulate this law in terms of wave optics and relate it to the resolution limits of various imaging systems. Furthermore, this modified Lagrange invariant is generalized for imaging along the z axis, resulting with the axial Lagrange invariant which can be used to analyze the axial resolution of various imaging systems. To demonstrate the effectiveness of the theory, analysis of the lateral and the axial imaging resolutions is provided for Fresnel incoherent correlation holography (FINCH) systems.

Eyebuydirect Canada allows you to add a polarized coating to your prescription or non-prescription sunglasses for an extra $40.