Photochromic or tinted lenses: which is better?
By See Better · Updated · 4 min read
The short answer
Photochromic lenses darken in sunlight and clear indoors, so one pair does two jobs. Fixed tints stay the same shade all the time. Choose photochromic lenses for convenience if you move in and out of the sun all day. Choose a dark fixed tint or prescription sunglasses if you drive a lot, because photochromic lenses barely darken behind a windscreen.
Key points
- Photochromic lenses react to UV light, darkening outdoors and clearing indoors.
- Most do not darken properly in a car, because the windscreen blocks UV.
- They get less dark in hot weather and take a few minutes to clear again.
- Whatever you choose, make sure the lenses block 100% of UV.
How photochromic lenses work
Photochromic lenses contain molecules that change shape when ultraviolet (UV) light hits them. Outdoors they absorb light and the lens darkens. Indoors, away from UV, they change back and the lens clears. You may know them by a brand name such as Transitions. They are sometimes called light-adaptive or light-adjusting lenses.
Darkening takes about half a minute to a minute. Clearing is slower: usually a few minutes before the lens looks clear again when you walk inside.
How fixed tints work
A fixed tint is a dye in or on the lens that never changes. It can be a light tint for comfort or fashion, or a dark sunglass tint. Common colours are grey, which keeps colours looking natural, and brown, which increases contrast. A gradient tint is darker at the top and lighter at the bottom.
Side by side
| Photochromic | Fixed dark tint (sunglasses) | Light fixed tint | |
|---|---|---|---|
| Indoors | Clear, or very nearly | Too dark | Slightly shaded |
| Outdoors in sun | Dark | Dark | Not dark enough |
| Driving in daylight | Stays mostly clear | Works well | Limited help |
| Night driving | Fine once fully clear | Never | Not recommended |
| Convenience | One pair for everything | A second pair to carry | One pair, less protection in bright sun |
| Cost | Higher than clear lenses | A second pair of glasses | Usually a small extra |
The three things to know about photochromic lenses
They do not darken much in the car. Car windscreens block most UV light, and UV is what triggers the change. Behind the wheel, standard photochromic lenses stay mostly clear. Some newer versions also react to visible light and darken a little in a car, but not as much as proper sunglasses. If you drive a lot in daylight, keep prescription sunglasses in the car.
Heat makes them less dark. Photochromic lenses get darkest in cold weather. On a hot summer afternoon in Gauteng they will darken, but not as deeply as on a cold winter morning.
They take time to clear. Walking from bright sun into a dim room, you will have a few minutes of slightly shaded vision. Most people stop noticing after the first week.
When photochromic lenses are the better choice
- You are in and out of buildings all day and do not want to carry two pairs.
- You tend to lose or forget sunglasses.
- Your eyes are sensitive to light.
- They are for a child or teenager who will not swap glasses.
When a fixed tint or sunglasses are better
- You spend long hours driving in daylight.
- You want the darkest and most consistent protection at the beach, on the water or playing sport.
- You want polarised lenses, which cut the glare that bounces off roads, water and car bonnets.
- You prefer a constant, light tint for comfort or for the look.
Many people end up with both: everyday glasses for general wear and prescription sunglasses that live in the car.
Do not forget UV protection
The shade of a lens tells you nothing about UV protection. A dark lens without a UV filter is worse than no sunglasses, because your pupils widen behind it and let more UV in. Photochromic lenses block UV whether they are dark or clear. For any tinted lens or sunglasses, check that it blocks 100% of UV, often labelled UV400. See how to choose sunglasses that protect your eyes.
Tints on See Better glasses
See Better's glasses packages include tinted lenses: R1199 with single vision, R1699 with bifocals and R2099 with multifocals, each including the eye test and a frame. Tell us how you spend your day, whether that is driving, working outdoors or sitting at a desk, and we will explain the tint options when we test your eyes. Reflections are a separate matter, covered in is anti-glare coating worth it?
Frequently asked questions
Do photochromic lenses work in the car?
Not well. Windscreens block most of the UV light that makes the lenses darken, so standard photochromic lenses stay mostly clear while you drive. Prescription sunglasses are better for driving in bright daylight.
Are photochromic lenses the same as transition lenses?
Yes. Transitions is a well-known brand of photochromic lens, and the name is often used for all lenses of this type.
Can I wear tinted glasses at night?
A very light tint is generally acceptable, but any noticeable tint reduces the light reaching your eyes and makes night driving harder. Never drive at night in sunglasses or dark tinted lenses.
Do photochromic lenses protect against UV?
Yes. Photochromic lenses block UV light at all times, including when they are clear indoors.
This article is general information and is not a diagnosis or a substitute for an eye examination. If you are worried about your eyes or your sight, see an optometrist or a doctor. Sudden loss of vision, eye injuries and severe eye pain are emergencies.
