20 Sunglasses Questions People Keep Asking, Answered Plainly

Search anything about sunglasses and you get a hundred answers that contradict each other. Darker is safer. Darker is worse. Polarised is essential. Polarised is a gimmick. We went through the questions people ask most and answered each one the way we would at an event booth, when someone has been squinting at the display for a while.

Let's Start With Your Eyes

Do sunglasses actually protect your eyes?

Yes, as long as they block UV. Years of UV exposure are linked to cataracts and growths on the surface of the eye, and a single long day on the water can sunburn the cornea, which feels like sand under your eyelids that night. The skin around your eyes is thin and burns too. Singapore sits close to the equator, so UV here is strong for most of the year.

What does UV400 mean?

It means the lens blocks light up to 400 nanometres in wavelength, which covers both UVA and UVB. That is the label to look for on any pair you buy. Every Sunday Shades frame is UV400 protected, but you should expect the same from anyone else.

Do darker lenses mean more protection?

No. Tint is about brightness, and UV protection is a separate property of the lens. A very dark lens with no UV protection can be worse than wearing nothing, because your pupils open wider behind the dark tint and more UV gets in. Check the label, not the shade.

Do you need sunglasses on a cloudy day?

Yes. UV passes through cloud more easily than most people expect, and a bright white sky is tiring to squint at for hours. If you are going to be outside for a long stretch, wear them whatever the sky looks like.

Lenses, Without the Jargon

Are polarised lenses worth it?

It depends on what bothers you most. Polarised lenses cut the glare that bounces off flat surfaces like water, wet roads and car bonnets. If you run beside a reservoir or play on a beach, you will notice the difference straight away.

The trade-off is screens. Some phones, sports watches, cycling computers and dashboards look dim or patchy through polarised lenses. We make both kinds. Pace, Max, Volt and Blaze have anti-glare lenses and are not polarised. Classic, Flare, Tempo, Coast, Surge, Cockpit and Junior are polarised. Neither is the "right" one. Ask yourself whether glare or screens annoys you more.

How can you tell if sunglasses are polarised?

Look at a phone or laptop screen through the lens, then turn your head or the glasses a quarter turn. If the screen goes dark or black at some angle, the lens is polarised. Not every screen reacts, so try a couple.

Which lens colour is best?

Grey keeps colours looking natural. Brown, amber and copper add contrast, which helps on overcast days and in changing light. Green sits somewhere in the middle. Honestly it is mostly a matter of what looks and feels easiest on your eyes, so try a few on. Colour does not change UV protection.

Do mirrored lenses actually do anything?

They do. The mirror coating on the outside bounces extra light away before it reaches your eye, which helps in very bright places like open water or white sand. It does not add UV protection by itself. The downside is that fingerprints and scratches show up more.

Do expensive sunglasses protect better?

Not automatically. A higher price usually pays for better optics, coatings, frame materials and durability. A cheap pair can block as much UV as a pricey one, and a pricey one can be a fashion tint with nothing behind it. Look for UV400 on the tag. If you want to be sure, many opticians can test a lens with a UV meter.

Getting the Fit Right

How should sunglasses fit?

Here is a 30-second check you can do in a shop or at home:

• The nose bridge should rest without pinching or leaving a deep mark.
• Your lashes should not touch the lens when you blink.
• The arms should hold your head gently, not squeeze above the ears.
• Shake your head, then look down at your feet. They should stay put.
• Smile as wide as you can. Your cheeks should not push the frame up.

Why do my sunglasses keep sliding down my nose?

Usually the frame was not shaped for your face. Sweat acts like oil, and if the frame is already sitting low on a low nose bridge, it only has one direction to go. You end up pushing them back up with sandy fingers while you wait for the next serve. Adjustable nose pads can help, and so can a different frame geometry, which brings us to the next question.

What is Asian Fit?

It is frame geometry made for lower nose bridges and higher cheekbones. A lot of sunglasses are designed around faces with a higher bridge and flatter cheeks, so on many of us they perch on the cheekbones, tilt forward and slip. Asian Fit puts the frame where your face actually is. It also suits many European faces. It is the reason we built Sunday Shades around Asian Fit and FitFlow™ in the first place.

What face shape suits which frame?

The usual rule of thumb is to pick the opposite of your face. Round faces look good in angular frames, square faces in softer curves. Take it or leave it. Fit and comfort matter more than shape, and a good frame is one you forget you are wearing.

Everyday Questions

Can wearing sunglasses make your eyes more sensitive to light?

There is no good evidence that it does. Daylight feels brighter for a moment when you take dark lenses off because your eyes had adjusted, not because they got weaker. If bright light bothers you more than it used to, see an optometrist.

Can you drive in sunglasses?

Yes, and they help a lot with glare off bonnets and wet roads. Two things to watch. Some dashboard and GPS screens can look dim through polarised lenses, so check yours before a long drive. And take them off in tunnels and at dusk. Never wear them at night, however good they look.

Do kids need sunglasses?

Yes. Children's eyes tend to let more UV reach the back of the eye than adult eyes do, and they spend a lot of time outdoors. Look for UV400 protection, a snug fit and a frame they will keep on. Our Junior frames are polarised and UV400 protected.

How do you clean sunglasses without scratching them?

Rinse, don't wipe. Wiping a dry lens drags sand and salt across it like sandpaper. Rinse with lukewarm fresh water, add a drop of mild washing-up liquid, rinse again, then pat dry with a microfibre cloth. Skip your T-shirt, tissues, hot water and glass cleaner, which can strip lens coatings.

Can you fix scratched lenses?

Not really. The toothpaste and baking soda tricks wear away the coating and usually make it look worse. A scratch at the very edge of the lens may never bother you. One in your line of sight will. Prevention is boring but works: use a case, rest the glasses lens-side up, and keep them away from your keys.

Why do sunglasses fog up when you exercise?

A warm, sweaty face meets a cooler lens and the moisture condenses. Frames with a little space between lens and cheek breathe better, and moving air clears the fog quickly. If they fog when you stop at a red light or between sets, that is normal. An anti-fog cloth helps if it bugs you.

How often should you replace sunglasses?

There is no expiry date. The UV protection built into a lens generally lasts, but coatings and the lens surface do not. Replace them when you have scratches in your line of sight, the coating starts peeling, the arms will not hold their shape, or you notice yourself squinting more than you used to. A pair that has survived two summers of beach volleyball has earned its retirement.

Got a question that did not make the list? Send it our way and we will add it. If you want to see how we put these ideas into frames, the range is at sundayshades.co.