From Inuit Snow Goggles to UV400: The Real History of Sunglasses

Before the lens, there was bone. Protecting your eyes from the sun is not a modern invention.

In Bali the sun forgives nothing. Between midday and three, the glare bouncing off sand, water and asphalt tires the eyes almost as much as looking straight up at the sky. We tend to think of sunglasses as a style decision, a pair that finishes an outfit. Yet shielding the eye from too much light is a human concern far older than fashion. From the Inuit to the first filtering lenses, the lesson fits in one sentence: a pair of sunglasses protects your eyes first, it dresses you second.

Before glass, how people already shielded their eyes

Long before tinted glass, several civilisations had worked out that light needed filtering to preserve sight. The Inuit, facing extreme glare off snow and ice under the Arctic sun, carved fine goggles from bone, wood or ivory, pierced with a single narrow horizontal slit. Excavated Arctic pairs have been dated to around a thousand years old. The principle is simple: by cutting the amount of light reaching the eye, the slit kills the glare, that discomfort and blurring caused by an excess of light.

Elsewhere, centuries later, other forms of protection appear. You will read everywhere that judges in twelfth-century China wore smoky quartz lenses to hide their eyes during hearings. It is a good story and nobody has ever produced the source, so take it as folklore rather than fact. What is not folklore is the idea underneath it: a lens placed in front of the eye changes how you see and how you are seen.

The same thread runs through the centuries: harsh light bothers people, and people have always found a way to cut it with whatever their era offered. What was still missing was the science of what, inside that light, actually damaged the eye.

Twentieth century: sunglasses become a tool of protection

Sunglasses as we know them, tinted lenses made in series on a frame built for comfort, only arrive at the start of the twentieth century. Aviation did much of the work of popularising them, pilots needing to cut glare at altitude, then cinema turned them into a style signal in the decades that followed.

But a dark tint does not protect your eyes. A darker lens is not a safer lens, and one particular case leaves you worse off than wearing nothing at all: a dark lens with no UV filter. The shade stops you squinting, your eyes open wide and relax, and unfiltered ultraviolet pours in from every angle. Put a real filter behind the same dark tint and the problem disappears entirely. Ultraviolet is invisible, and over the years it burns the cornea and clouds the crystalline lens.

It was in the second half of the twentieth century that optical research established the link clearly between UV exposure and eye health. Manufacturers then began developing specific treatments able to filter that radiation independently of the tint. Sunglasses stopped being an accessory and became a genuine protective device.

What actually protects your eyes today

The quality of a sun lens reads on two criteria: its filtration category and its anti-UV treatment, never its colour alone. Lenses are graded 0 to 4 according to how much visible light they let through, from the palest to the darkest. We break down those categories, and the one that genuinely suits the Bali sun, in sunglasses lens categories, from 0 to 4.

That category says nothing about UV protection, which has to be guaranteed separately by the maker, usually under the UV400 marking. UV400 says one thing precisely: the lens blocks every wavelength up to 400 nanometres, which covers all of UVA and UVB. A lens that stops at 380 lets part of the UVA through. The marking says nothing about how dark the lens is, nothing about polarisation and nothing about optical quality. A pale category 1 lens can be UV400. A very dark category 3 lens can have no filter at all. Ask for the marking, not for the tint. It is also what separates a serious sun lens from a tourist gadget, a subject we cover in real or fake sunglasses. Polarisation, a distinct treatment that cuts reflections off water and asphalt, usefully completes that protection without replacing it, as we explain in polarized lenses or UV protection.

Here the exposure is not theoretical. Bali sits eight degrees off the equator, where the UV index regularly reaches 11 and above, the top of the scale. Sand throws roughly 15% of that ultraviolet back up at your eyes, water rather less, and thin cloud barely slows UV down at all: overcast is not the same as safe. Years of that without filtration is how pterygium turns up, the fleshy growth on the white of the eye that every optician here sees on surfers and fishermen, and how a cataract arrives earlier than it should.

On our side that translates into one rule. Every Classic sun pair leaves the store with polarised UV400 lenses as standard. If you wear a correction, the same lenses exist to your prescription, in Essilor, ZEISS or Hoya, with a photochromic option that many people end up preferring for a full year in Bali.

Understanding that distinction, between tint, category and UV filtration, is what lets you choose a pair of sunglasses for the right reasons rather than for its looks alone.

Shielding your eyes from the sun has never been about fashion. We think about it with every pair cut in Canggu.

What this history changes in the Canggu workshop

From the Inuit to modern optical laboratories, the conclusion does not move: protecting the eye is never a detail. Which is why every sun frame cut by hand in the Canggu workshop leaves with lenses that genuinely filter UV, chosen for their optical quality as much as for their look.

The work does not stop at the shape of the frame. It carries on into the lens you fit to it. That is what we apply to every pair that leaves Canggu.

This article is informative and cultural in purpose. It does not replace medical advice. For any discomfort or vision problem, consult an ophthalmologist or a qualified optician.