What are Polarised Sunglasses? Polarised sunglasses cut down glare off reflective surfaces, such as water, snow and glass, to a much greater extent than regular sunglasses. They also give your eyes 100% protection against UVA and UVB rays. The lenses have a special chemical applied to them to filter out the horizontal light rays that bounce off reflective surfaces that cause glare. Polarised sunglasses only allow vertical light rays to reach your eyes. Normal sunglasses don’t have this filter. This means that the image you see with polarised lenses is a bit darker than usual, but objects look crisper and clearer, and details are easier to see.
Who benefits most from polarised sunglasses?
Anyone who spends a lot of time outdoors, particularly in the harsh sun, near water or snow, will benefit from polarised sunglasses. Polarised sunglasses protect your eyes all year round.
Advantages of Polarized sunglasses
Wearing polarised sunglasses reduces strain to the eyes, which may otherwise lead to headaches. They enable you to see with full clarity, even when the sun is very intense. They’re helpful when driving during the day, so that your vision isn’t temporarily impaired by reflective surfaces such as car windows or bonnets. What does UV400 mean? High levels of sunlight exposure can cause serious and sometimes irreversible damage such as inflammation, cataracts, pterygium (abnormal tissue growth over the eye), eyelid cancers and retina degeneration. Ultraviolet radiation is what causes this damage. The dangerous UV rays are UVA and UVB. UV400 is the category which blocks all light rays with wavelengths up to 400 nanometers, which includes UVA and UVB. All Zedrays sunglasses are classified UV400 so block out all UVA and UVB rays What is Category 3? In Australia, sunglasses and fashion spectacles are classified into five categories by their performance suitability for use in certain conditions as follows,:
- Lens category 0: Fashion spectacles – These are not sunglasses, as they have a very low ability to reduce sun glare. They provide limited or no UV protection.
- Lens category 1: Fashion spectacles – Like category 0 lenses, these are not sunglasses; however, they do provide limited sun glare reduction and some UV protection. Fashion spectacles with category 1 lenses are not suitable for driving at night.
- Lens category 2: Sunglasses – These sunglasses provide a medium level of sun glare reduction and good UV protection. They are not suitable for driving at night or under dull light conditions.
- Lens category 3: Sunglasses – These sunglasses provide a high level of sun glare reduction and good UV protection. They are not suitable for driving at night or under dull light conditions.
- Lens category 4: Sunglasses – These are special purpose sunglasses that provide a very high level of sun protection against extreme sun glare and good UV protection, they are not suitable for road use and driving.
All Zedrays sunglasses are tested and classified as Category 3, meaning they give a high level of sun glare reduction and good UV protection. They are not suitable for driving at night or under dull light conditions.  https://www.aao.org/eye-health/glasses-contacts/polarized-lenses  https://www.lentiamo.co.uk/glossary/sunglasses-uv400-filter.html  https://www.productsafety.gov.au/standards/sunglasses-fashion-spectacles  https://wiki.cancer.org.au/policy/Position_statement_-_Eye_protection