Gradient lenses explained: dark at the top, light at the bottom, and who that actually suits

A gradient lens is tinted more at the top than at the bottom, usually dark grey or brown fading to nearly clear. The idea is simple: sunlight comes from above, so the top of the lens does the shading, while the clear lower half gives you an undimmed view of whatever is below your eyeline, a dashboard, a book, a phone. That works exactly as well as the assumption holds. Driving in ordinary sun, reading outdoors and walking a city street, it holds. On water, snow, sand or a road at low sun, where the light comes up from below, it fails, because the clear half passes the reflection straight through. Gradient is not photochromic; it is a fixed pattern, not a changing one. And it can be polarized, which fixes its main weakness for driving.

How a gradient lens is made

Plastic lenses are tinted by dipping them in a heated dye bath. Dip the whole lens for the same time and you get an even tint. Dip it top-first and withdraw it slowly, and the top spends longer in the dye than the bottom; the result is a smooth fade from dark to light. That is a gradient. Some are double gradients, darker at both top and bottom and lighter in the middle, for sun above and glare below with a clear band for the horizon.

The tint colour can be anything a plain lens can be. Grey and brown are the common ones.

Where it works

Driving in ordinary daylight. Sun and sky through the top of the lens; dashboard, instruments and the road just ahead through the lighter bottom. This is the case gradient lenses were made for and where they are most often sold.

Reading and screens outdoors. Look up into the sun through the dark half; look down at the page or the phone through the light half.

City streets. Light from above, buildings around, little reflected from below.

Fashion. The fade shows the eyes, which is why gradients are common in dress frames. That is a legitimate reason to choose one.

Where it fails

Anything that throws light up from below reaches your eye through the clear half of the lens with nothing in the way.

• Water. The whole point of a water lens is the glare off the surface, which arrives from below. A gradient passes it. Our fishing post and sailing post explain why water lenses are dark all the way down.
• Snow. Same, worse. Snow reflects most of the light and UV that hits it.
• Sand. A beach at noon is a reflector.
• Low sun on a road. The road is the reflector, and it is below your eyeline. Our low sun post covers that light.

For all of those, a lens with a uniform tint, or a mirror over a dark base, is the right tool.

Gradient versus photochromic

They get confused because both involve a lens that is not uniformly dark. They are unrelated.

• A gradient lens has a fixed pattern of tint. It does not change. It is dark at the top all the time.
• A photochromic lens has a uniform tint that changes: darker in UV, lighter without. Our photochromic post covers it.

A lens can in principle be both, but in practice you choose one.

Can a gradient be polarized?

Yes. The polarizing film is laminated in or coated on; the gradient is the dye. They do not interfere. A polarized gradient is a good driving lens: the gradient handles sun from above and keeps the dashboard clear, and the polarization removes the road glare that the clear bottom half would otherwise pass. Our polarized vs non-polarized post covers what the film does.

One caution carries over: through the light bottom half, an LCD dashboard is easier to read, but a polarized film still blocks some LCDs at some angles. Our screen post explains.

Where ours sit

All five of our lenses are uniform tints, not gradients, and all are polarized. Uniform because three of them are water and snow lenses, where a gradient is the wrong tool, and because a uniform medium tint is the more versatile everyday lens. If your sunglasses live in the car and you want the dashboard clearer, a polarized gradient from another maker is a reasonable choice, and the lens colour guide applies to its tint just the same.

Frequently asked questions