Everything you need to know about sunglasses

While sunglasses are often a fashion style statement, they serve to protect our eyes. Ultra-violet (UV) rays from the sun may contribute to damaging the cells in our eyes, which could lead to issues such as cataracts, macular degeneration and photokeratitis (sunburn of the cornea), which can result in blurred vision, light sensitivity, and/or even temporary blindness.

Also, important to note, even if the sun is not shining brightly on a cloudy day, UV rays can still damage eyes.

Sunglasses also help to protect eyes from sand, dust and wind.

Polarised, gradient, mirrored, photochromic…

• Polarised sunglasses help to reduce glare from bright light when it reflects off flat surfaces. This is a good option for outdoor water activities such as sailing, fishing or a beach day. People also tend to use polarised lenses for driving as it helps to minimise the glare from windows.
• Gradient lenses are a good choice for driving as the top of the lens is the darkest, which helps protect against sunlight, whereas the bottom half of the lens is lighter, allowing drivers to see the dashboard clearly.
• An anti-reflective coating can also assist with minimising glare.
• Mirrored sunglasses work by limiting the amount of light that enters the eyes.
• Photochromic lenses automatically adjust to changing light, with the lenses becoming darker on bright days, and lighter when conditions get darker. Something to note here is that these lenses do not work well when driving a car as UVB rays do not penetrate your windshield.

Lens tints
Darker shades assist with glare and help to reduce eyestrain in moderate-bright conditions.

Light colours (yellow/gold/amber/rose/vermillion) work well in moderate- to low-level light conditions as they assist with depth perception and enhance contrast, improving visibility of the surroundings.

Lens coatings
A hydrophobic coating assists to repel water, while an anti scratch coating helps improve durability. An anti-fog coating is useful for humid conditions or high-energy activities, and a mirrored coating helps to reduce glare.

Lens material
Glass offers great clarity and scratch-resistance but is heavy.
Polyurethane (a type of plastic) offers great clarity, impact resistance, is flexible and lightweight but is expensive.
Polycarbonate (a type of plastic) offers good clarity, great impact-resistance, and is lightweight but less scratch resistant.

Acrylic, an inexpensive alternative to polycarbonate, is suited for casual or occasional-use sunglasses. It is less durable and optically clear.