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Plain answers to what people actually ask about sunglasses. What polarisation removes, which tint suits which light, what the size numbers mean, and what a label does and does not tell you. Sourced where a claim needs a source, and plain about the limits of what anyone has published.

A two-lane road at night with oncoming headlights blooming into starbursts on a wet surface

Choosing · September 30, 2026 · 4 min Yellow lenses for night driving: what the evidence says, and why no tint belongs on a night road Yellow night-driving glasses are sold to cut headlight glare and sharpen the road. Controlled testing finds they do not improve night driving performance and can make it slightly worse, because any tint removes light you need. Here is what yellow lenses actually do, what the studies found, and what does help on a night road.

A cold morning trail with mist hanging in still air among pine trees and frost on the ground

Care · September 30, 2026 · 4 min Why sunglasses fog up, and what actually stops it Sunglasses fog when the lens is colder than the air touching it and that air is humid. It happens when you stop moving, when you breathe upward, and when you step from cold into warm. Here is the physics in one paragraph and the fixes ranked by how well they work.

The view from a high-altitude cockpit window over a blinding white cloud deck under deep blue sky

Lenses · September 30, 2026 · 3 min Why pilots do not wear polarized sunglasses, and what they wear instead Polarized lenses can hide the glint off another aircraft, black out LCD instruments, and show stress patterns in a laminated windscreen. The FAA advises against them in the cockpit. What pilots wear instead is a non-polarized neutral grey with strong UV blocking and a thin-armed frame that fits under a headset. Here is the reasoning, and what it means for anyone who reads screens in bright light.

Close-up of the temple arm of a dark plastic frame resting on a wooden table beside a glass of water

Fit · September 30, 2026 · 4 min Why do my sunglasses give me a headache? Six causes, in order of likelihood A headache from sunglasses is almost always the frame, not the lens: too tight at the temples, too heavy on the nose, or pressing behind the ears. Less often it is the lens: distortion, a tint too dark for the light, or an unaccustomed polarized view. Here is how to tell which, and what to do about each.

A shopping mall atrium flooded with skylight, a polished floor reflecting the glass roof, no people

Lenses · September 30, 2026 · 4 min Is wearing sunglasses indoors bad for your eyes? What actually happens Wearing sunglasses indoors does not damage your eyes. The one real effect is that your eyes adapt to the dimness, so bright light feels harsher when you take them off. There are good reasons to wear them inside: migraine, light sensitivity, recovery from eye surgery. Here is what is true and what is myth.

A high mountain ridge under a hard pale sky, intense sun on rock and snow

Lenses · September 30, 2026 · 4 min UV400 vs polarized: they are not the same thing, and you want both UV400 and polarized describe two different properties. UV400 is about protecting your eyes from ultraviolet light. Polarized is about removing glare. A lens can be either, both or neither. Here is how to read the labels and what to check.

A wide beach at noon under a cloudless sky with a single beach umbrella casting a short dark shadow

Choosing · September 30, 2026 · 4 min The UV index and when to wear sunglasses: a number, a time of day, and a rule of thumb The UV index is a forecast of ultraviolet strength on a scale from 0 upward. From 3, eye and skin protection is advised. It peaks around solar noon, is higher in summer, at altitude, near the equator and over snow or water, and is not the same as temperature or brightness. Here is how to read it and the rule of thumb that needs no app.

A row of clear circular glass lens discs standing in a wooden rack on an optician's white workbench

Choosing · September 30, 2026 · 4 min Sunglasses if you wear glasses: the four options, honestly compared If you need vision correction, you have four ways to wear sunglasses: fit-over frames that go over your glasses, clip-ons, prescription sunglasses, or contact lenses under ordinary sunglasses. Each trades cost, optics and convenience differently. Here is what each does well and badly.

A steel rule lying on a dark surface with its tick marks running out of focus

Fit · September 30, 2026 · 4 min Sunglasses measurements explained: what 60-15-145 means and which number decides fit The three numbers on a sunglasses arm are lens width, bridge width and temple length, in millimetres. The number that actually decides whether a pair fits, the frame width, is usually not printed. Here is how to read all four and measure your own face.

Three clear lens blanks on black velvet under a single light, each catching a different highlight

Lenses · September 30, 2026 · 4 min Sunglasses lens materials: glass, polycarbonate, TAC and CR-39, compared honestly Four materials make almost every sunglasses lens. Glass is the clearest and scratches least but is heavy and can shatter. Polycarbonate is the toughest. TAC is light, cheap and the usual home of a laminated polarizing film. CR-39 sits between. Here is what each does well, what it does badly, and how to tell which you have.

Extreme close-up of water beading into spheres on a glossy hydrophobic surface against a dark background

Lenses · September 30, 2026 · 4 min Sunglasses lens coatings explained: hard coat, anti-reflective, hydrophobic and mirror A modern sunglass lens is a stack. On top of the tinted lens sit up to four coatings, each doing one job: a hard coat against scratches, an anti-reflective layer on the back to stop light bouncing into your eye, a hydrophobic layer to shed water and smudges, and sometimes a mirror on the front. Here is what each does, which ones are worth paying for, and which you cannot see.

Five squares of grey glass on a lightbox stepping evenly from almost clear to nearly black

Lenses · September 30, 2026 · 4 min Sunglasses lens categories and VLT: what category 3 means and why it is not a UV rating Lens categories 0 to 4 describe how dark a lens is, measured as visible light transmission, the percentage of visible light that passes through. Category 3 is the everyday sunglasses band. Category 4 is too dark for driving. None of it says anything about UV protection or polarization.

A car dashboard in full sun with heat shimmer rising from the black vinyl

Care · September 30, 2026 · 4 min Sunglasses left in a hot car: what the heat actually does to them A car dashboard in summer sun reaches temperatures that warp plastic frames, craze anti-reflective coatings and can delaminate a lens. The tint and the UV block survive; the frame shape and the coatings do not. Here is what happens at what temperature, and where to keep them instead.

A small clear silicone nose pad and a tiny screwdriver on a white tabletop

Fit · September 30, 2026 · 4 min Sunglasses keep slipping down your nose? The three causes and the fix for each Sunglasses slip for three reasons: the frame is too wide for your face, the temple arms do not grip behind the ears, or the bridge is the wrong shape for your nose. Each has a different fix, from a frame that fits to a one-dollar pair of silicone nose pads. Here is how to tell which is yours.

Small sheets of acetate in tortoiseshell, black and clear stacked on a workbench beside a bar of matte nylon

Lenses · September 30, 2026 · 4 min Sunglasses frame materials: acetate, injected plastic, TR90, nylon and metal, compared honestly The frame decides weight, flex, how it survives being sat on, and whether it can be adjusted. Acetate is the premium plastic, cut from sheet and polished. Injected plastic is cheaper and lighter. TR90 and nylon flex without breaking. Metal adjusts and lasts but weighs more and corrodes near salt. Here is what each is, what it costs you, and how to tell which you have.

A plain oval hand mirror on a light wooden dresser reflecting a bright window, beside a steel rule

Fit · September 30, 2026 · 4 min Sunglasses for your face shape: the one rule that works, and the ones that do not Face-shape guides all say the same thing in six variations: pick a frame that contrasts your face's dominant line. That rule works. What matters more, and what the guides skip, is width. A frame that is the wrong width looks wrong on every face shape. Here is the rule, the six shapes, and how to measure.

An interstate highway at golden hour from high up, the road running straight to the horizon between dry fields

Choosing · September 30, 2026 · 4 min Sunglasses for truck drivers: ten hours of glare, a high seat, and a dashboard full of screens Truck driving is the hardest daytime driving case: ten hours behind glass, a high seat that sees more road glare, sun through the side window all afternoon, and a dashboard full of LCD displays. The lens is a medium polarized brown or grey. The frame is light, and the screens get checked before the lens is bought.

A groomed ski slope in flat overcast light where the surface texture is almost invisible

Choosing · September 30, 2026 · 4 min Sunglasses for skiing and snow: when polarized helps, when it hides the ice On snow in bright sun, a dark mirrored lens with side coverage is right and polarized is a bonus. In flat light, polarized can hide the shine that tells you where the ice is, and a low-light tint beats a dark one. Here is how the choice changes with the sky, and when goggles are the honest answer.

An empty mountain road at dawn with hairpin bends climbing away and mist in the valley

Choosing · September 30, 2026 · 4 min Sunglasses for motorcycle riding: wind, impact and the helmet decide more than the tint On a motorcycle the lens is the last thing to choose. First the frame has to fit under a helmet, seal against wind at speed, and survive a stone. Then a medium brown or grey polarized lens for the road. Here is the order of priorities, what a helmet visor does and does not replace, and why very dark lenses are a mistake under a tinted visor.

A wooden garden bench in strong midday sun with slats casting sharp shadows on dry grass

Lenses · September 30, 2026 · 4 min Do sunglasses block vitamin D? No. Your skin makes it, not your eyes Vitamin D is made in the skin when UVB light reaches it. The eyes play no part. Sunglasses block UV reaching the eye, which is exactly what they should do, and have no effect on how much vitamin D your skin makes. Here is where the myth came from and what actually decides your vitamin D.

A quiet clinic waiting room with pale walls, a single chair and a window with a half-drawn blind

Choosing · September 30, 2026 · 4 min Sunglasses after cataract surgery or LASIK: why your surgeon insists, and for how long After cataract surgery the new artificial lens lets more light through than the old cloudy one did, and after LASIK the cornea is healing and light-sensitive. Both mean UV-blocking sunglasses outdoors, and for a while indoors. Here is what each procedure changes, how long the sensitivity lasts, and what the sunglasses need to be. Not medical advice; your surgeon's instructions come first.

Five sheets of tinted glass in a row, grey, brown, deep blue, pale blue and red-orange, each casting a coloured shadow

Lenses · September 30, 2026 · 5 min Sunglass lens colour guide: what grey, brown, blue, ice blue and red each do to the light Every lens colour edits the light differently. Grey dims evenly, brown lifts contrast, and mirrors turn away a slice of light before it reaches the tint. Here is what each of the five common tints does, and which light it is for.

A vast snowfield under a cloudless sky at altitude, blinding white with the horizon lost in glare

Choosing · September 30, 2026 · 4 min Snow blindness: what it is, how fast it happens, and the sunglasses that prevent it Snow blindness is a sunburn of the cornea from UV reflected off snow. It takes a few hours of exposure, the symptoms arrive six to twelve hours later, and it is fully preventable with lenses that block UV and cover the sides. Here is the timeline, the symptoms, and what to wear.

A wide beach under a uniformly bright overcast sky with wet sand reflecting the glow and no shadows anywhere

Choosing · September 30, 2026 · 4 min Should you wear sunglasses on cloudy days? Yes, and here is which lens Clouds block much of the visible light and far less of the UV: on an overcast day 80 percent or more of ultraviolet can still reach you. Sunglasses on a cloudy day are about UV and about contrast, not darkness. Here is which lens works and why a dark one is the wrong choice.

Extreme close-up of a fine scratch across a dark glossy surface catching a line of light

Care · September 30, 2026 · 4 min Scratched sunglasses lens: what can be fixed, what cannot, and why toothpaste makes it worse A scratch in a sunglasses lens cannot be removed. Every home remedy, toothpaste, baking soda, car wax, either polishes off the coating around the scratch or fills it temporarily. Here is what each one actually does, when a scratch matters, and when to replace the lens.

A bright construction site in hard sun with stacked rebar, a concrete slab and an orange cone casting a sharp shadow

Choosing · September 30, 2026 · 4 min Safety sunglasses and impact ratings: what Z87 means and when ordinary sunglasses are not enough Ordinary sunglasses are not safety glasses. A safety rating means the lens and frame passed a specified impact test; the common mark in the US is Z87 from the ANSI standard. Construction, workshops, yard work and some sports need that rating. Here is what the marks mean, what tinted safety lenses exist, and why our sunglasses do not carry one.

A wet road in low sun throwing a sheet of white glare toward the camera

Lenses · September 30, 2026 · 5 min Polarized vs non-polarized sunglasses: what the filter actually changes Polarized and non-polarized sunglasses can be equally dark and equally UV-safe. The difference is glare. Here is what a polarizing filter removes, when it matters, when it gets in the way, and how to tell which you own.

A smartphone lying face up on a car dashboard in direct sun with a faint rainbow sheen on its dark screen

Lenses · September 30, 2026 · 4 min Why polarized sunglasses make your phone screen go dark or rainbow Polarized sunglasses can make a phone, car display or fuel pump screen go dark, dim or show rainbow bands. The screen is not broken and neither are the glasses. Here is what is happening and the three ways around it.

A country lane seen from a doorway, half in bright sun and half in the shade of a porch, with a hard light line across the path

Lenses · September 30, 2026 · 4 min Photochromic vs polarized sunglasses: one changes darkness, the other removes glare Photochromic lenses darken in UV light and lighten without it. Polarized lenses remove reflected glare at a fixed darkness. They solve different problems and can be combined. Here is what each does, how fast photochromic really changes, and why it does not darken in a car.

Extreme close-up of a curved mirrored surface reflecting a beach and sky

Lenses · September 30, 2026 · 4 min Mirrored vs polarized sunglasses: one is a coating, the other is a filter Mirrored and polarized are not alternatives. A mirror is a reflective coating on the outside of the lens that turns away some light before it enters. Polarization is a film inside the lens that removes reflected glare. A lens can be either, both or neither, and the two do different jobs.

Fit · September 30, 2026 · 4 min Low nose bridge sunglasses: why standard frames slide, and what "Asian fit" actually changes Most sunglasses are designed around a nose bridge that sits high between the eyes. If yours sits lower, or your cheekbones sit higher, a standard frame perches on the tip of the nose, rests on the cheeks, and slides. Low-bridge frames change three measurements to fix it. Here is what they are, how to tell if you need one, and what to do with a frame that is close.

A sandy playground in hard summer sun with an empty swing casting a sharp shadow

Choosing · September 30, 2026 · 4 min Kids' sunglasses: what to look for, and why UV matters more for children than adults A child's eye lets more UV through to the retina than an adult's, and children spend more hours outside. Kids' sunglasses need real UV protection, a shatter-resistant lens, a frame that stays on, and a strap. Colour and darkness matter less than any of those. Here is the checklist.

A still lake at midday with the sun reflected as a blinding streak across the surface

Lenses · September 30, 2026 · 4 min How to tell if sunglasses are polarized: three tests that take a minute You can check whether any pair of sunglasses is polarized in under a minute with a phone screen, a second pair of sunglasses, or a window in daylight. Here is how each test works and what it will and will not tell you.

A precision screwdriver set fanned out on a dark cloth beside tiny screws and a folded microfibre cloth

Care · September 30, 2026 · 4 min How to fix loose sunglasses: tightening the hinge, replacing a screw, and when to stop Loose sunglasses are almost always a hinge screw that has backed out. A small screwdriver and a quarter turn fix it. A lost screw is a two-dollar kit. A stripped screw or a cracked hinge is an optician's job. Here is each fix in order, and the two things that make it worse.

A folded grey microfibre cloth and a small spray bottle beside a running tap on a white counter

Care · September 30, 2026 · 4 min How to clean sunglasses without scratching the lenses Rinse first, then wash with a drop of dish soap and lukewarm water, dry with a clean microfibre cloth. Never wipe a dry lens, never use paper, and never use anything with ammonia or alcohol on a coated lens. The same method is right for polarized lenses.

An old leather sunglasses case with worn edges and a faded interior on a wooden desk

Care · September 30, 2026 · 4 min How long do sunglasses last, and does UV protection wear off? UV protection built into the lens material does not wear off. UV protection applied as a surface coating can. What ends a pair's life is usually scratches, a coating that has flaked, or a frame that has loosened, not an expired lens. Here is what actually ages and when to replace.

A flat sea horizon at midday, the sky deep blue at the top of the frame grading to pale white at the water

Lenses · September 30, 2026 · 4 min Gradient lenses explained: dark at the top, light at the bottom, and who that actually suits A gradient lens is darker at the top than the bottom. The idea is sun from above, a clear view of the dashboard or a book below. It works for driving and reading and fails on water, snow and any surface that throws light up from below. Here is what gradient does, how it differs from photochromic, and whether it can be polarized.

A straight winter road with the sun sitting on the horizon at the end of it and long tree shadows across the tarmac

Choosing · September 30, 2026 · 4 min Driving into low sun: the lens, the visor, and the four habits that matter more Low sun ahead is the worst daytime driving light: the sun sits in your eyeline, the road throws it back at you, and a dirty windscreen turns it into a white sheet. A polarized brown or grey lens removes the road glare. The visor, a clean windscreen, following distance and knowing the times of day do the rest.

Extreme close-up of dry cracked clay in hard sun with fine fissures radiating from a point

Choosing · September 30, 2026 · 4 min Do sunglasses prevent wrinkles and crow's feet? Two ways, and one of them is squinting Sunglasses reduce wrinkles around the eyes in two ways. They stop you squinting, which is the repeated muscle movement that folds the skin at the outer corners into crow's feet. And a large lens shades the thin skin around the eye from UV, which is the main cause of skin ageing. Here is what each does and which frames do it best.

A laptop screen glowing cool blue-white in a dark room at night, light spilling across a desk

Lenses · September 30, 2026 · 4 min Do sunglasses block blue light? Yes, some of it, and here is which tints block most Every tinted lens reduces blue light, because blue is part of visible light and a tint dims visible light. Brown, amber and yellow tints remove more blue than grey. What sunglasses are not is a fix for screens at night, where the issue is brightness and timing rather than a wavelength. Here is what the evidence supports.

A clay tennis court at midday from the baseline with brilliant white lines and a yellow ball resting on the line

Choosing · September 30, 2026 · 4 min The best sunglasses for tennis and baseball: tracking a ball against the sky Ball sports ask one thing of a lens: make a fast ball stand out against sky, lights and a background. A brown, amber or red-mirror lens does that by raising contrast; grey does not. Polarized helps on clay and turf glare and has one caution under stadium lights. Here is the lens, the frame and the reason.

A yellow sea kayak resting on a sandy shore at the water's edge with sun glitter on flat bright water

Choosing · September 30, 2026 · 4 min The best sunglasses for sailing and kayaking: glare from every direction, and the strap that saves them On the water, light comes from the sky and again off the surface, and it comes from every side. The sunglasses that work are polarized, mirrored over a dark base, close-fitting with side coverage, and on a strap, because the ones that go overboard are the ones without one. Here is the lens, the frame, and what salt does.

An empty running track at dawn with long shadows across the lanes and dew on the infield

Choosing · September 30, 2026 · 4 min The best sunglasses for running: light, secure, and the right tint for the route For running, the frame matters more than the lens: it has to stay put without pressure and let air through so it does not fog. For the lens, brown or amber for roads and trails in changing light, grey for open flat sun. Polarized helps on roads, matters less on trails.

A high alpine trail above the treeline in hard midday light with pale scree and a distant ridge in haze

Choosing · September 30, 2026 · 4 min The best sunglasses for hiking: altitude changes the answer For hiking below the treeline, a brown polarized lens reads the trail through changing light. Above it, and on snow, UV is stronger and the ground reflects it back; the lens needs to be darker, the UV claim needs to be real, and coverage at the sides matters. Here is how the answer changes with the terrain.

A golf green in early morning light with dew on the grass and the flag casting a thin shadow

Choosing · September 30, 2026 · 4 min The best sunglasses for golf: the polarized question, answered honestly Golf is the one sport where polarized is a genuine debate. Polarization removes the sheen on a green that some players use to read grain, and lifts contrast that helps others track a ball. Here is the trade-off and which lens colour suits the course.

Shallow clear water over a sand flat from a boat bow, with a fish shadow visible beneath the surface glitter

Choosing · September 30, 2026 · 4 min The best sunglasses for fishing: why polarized is non-negotiable and which tint to pick For fishing, polarized is not optional. It is the only thing that lets you see through the surface instead of the glare on it. Which tint to pick depends on the water: a mirror for open blue water, a brown for flats and rivers.

A narrow tarmac road climbing through forest with patches of hard sun and deep shade alternating along it

Choosing · September 30, 2026 · 4 min The best sunglasses for cycling: coverage, the shade problem, and why the pros ride brown Cycling puts your eyes into wind, grit and constantly changing light at speed. The lens that copes is a medium brown or amber that reads the road through sun and shade; the frame that copes covers the eye and does not fog on a climb. Polarized helps on wet roads and hurts on some bike computers.

A driver's view of a straight highway at golden hour with the sun low and ahead

Choosing · September 30, 2026 · 5 min The best sunglass lens colour for driving, and the two that are not For driving, a neutral grey lens is the safest all-round choice, brown is better in low or variable sun, and dark blue or heavily mirrored lenses should stay off the road. Here is why, with the one rule that matters more than colour.

A bright beach boardwalk in hard summer sun with white railings and sea glitter beyond

Choosing · September 30, 2026 · 5 min Are cheap sunglasses bad for your eyes? What price buys, and what it does not A cheap pair with real UV protection is safer than an expensive pair without it. Price does not decide UV blocking, polarization or optical clarity. Here is what the money actually buys, what to check on any pair, and the one thing that makes a cheap lens dangerous.

A polished walnut desk with a brass magnifying glass, an old leather ledger and round smoked-glass lens blanks in a wooden tray

Lenses · September 30, 2026 · 5 min A short history of sunglasses: from Inuit slit goggles to the polarizing film Sunglasses are older than glass lenses. Arctic peoples cut slits in bone and wood to beat snow glare thousands of years ago. Smoky quartz shaded Chinese judges' eyes in the twelfth century. Tinted spectacles were a medical curiosity until the 1920s, when mass production, Hollywood and aviation made them an object. The polarizing film came in 1936. Here is the line from there to the lens on your face.