When you're ordering replacement mirror glass and the listing asks whether you need convex or wide angle, it's easy to just guess and hope for the best. But the two types give you a noticeably different view - and fitting the wrong one means you're either losing blind spot coverage you had before, or adjusting to a view that doesn't match what you're used to.
Here's how they actually differ and how to work out which one your car takes.
What convex mirror glass actually does
Convex glass curves outward towards you. That curve compresses the image slightly - things appear a little smaller than they actually are, but you see a wider area than you would with a completely flat surface.
It's the standard type on the passenger side of most UK cars. From the driver's seat, the passenger mirror is further away and at a shallower angle, so a convex glass gives you the coverage you need without distorting the image too much. You get a natural, usable view of the lane alongside and behind you.
What wide angle mirror glass does differently
Wide angle glass - sometimes listed as aspheric or blind spot glass - has a more pronounced curve, particularly towards the outer edge. That sharper angle pulls in a significantly wider field of view, which directly reduces the blind spot alongside the car.
On the driver's side, the mirror is closer to you and the angle to the rear is steeper. A standard convex glass on that side leaves a blind spot that wide angle glass largely eliminates. Which is why most modern UK cars come with wide angle as standard on the driver's side.
Some cars take wide angle on both sides - usually larger vehicles, vans, or anything where the manufacturer decided full blind spot coverage was worth having all round. It's less common but not unusual.
So which side takes which?
The most common setup on UK cars:
- Driver's side - wide angle
- Passenger's side - convex
Some cars take wide angle on both sides. What you won't find is wide angle on the passenger side only - if a car has wide angle on one side, it's always the driver's side at minimum.
The safest way to check isn't guessing by the side - it's looking at the glass you're replacing. Hold the old mirror up and look at the curvature. Convex has a gentle, even curve across the whole surface. Wide angle has a noticeably sharper curve, especially at the outer edge - you can see it clearly if you look along the face of the glass at an angle.
If the old glass is too broken to check, look up your make, model and year in the wing mirrors collection - the listings show which type fits each side for your specific car.
Does it matter if you fit the wrong type?
Yes, practically speaking. It won't damage anything - the glass clips on regardless of type - but the view will be different to what you had before, and that takes some adjusting to.
Fitting convex where you had wide angle means a smaller field of view and more blind spot. That's a real safety reduction on the driver's side. Going the other way - fitting wide angle where you had convex - gives you more coverage but a slightly more compressed image that can feel unfamiliar at first.
Neither is dangerous in absolute terms, but matching what the car came with is the right call.
What about heated vs non-heated - does that affect the type?
No - heated and non-heated are separate from convex and wide angle. You can get heated convex, non-heated convex, heated wide angle, and non-heated wide angle. They all clip on the same way.
If your current mirror is heated (you'll see a faint wire element through the glass), make sure your replacement is heated too. The clip-on fitting is identical but the heated version has two connector pins on the back for the heating element.
Common questions
Is wide angle the same as aspheric?
Yes - wide angle, aspheric, and blind spot glass all refer to the same thing. Wide angle is the most commonly used term in the UK. You might see aspheric on some listings or older part catalogues, but they're the same product.
My car has wide angle on both sides - is that normal?
It's less common than driver's side only, but yes, some cars come with wide angle on both sides from the factory. Larger cars and some European models in particular. If that's what your car had originally, replace both with wide angle.
Can I upgrade from convex to wide angle for better visibility?
Technically the glass will clip on either way. But the view will be different to what the mirror housing was designed for, and on the passenger side the angle and positioning of the housing is set up for convex glass - so you might not get the full benefit of wide angle in that position anyway. For the driver's side, sticking with wide angle is always the better choice.
How do I tell which type I currently have?
Look at the face of the glass at a low angle, along the surface. Convex has a gentle even curve. Wide angle has a noticeably sharper curve at the outer edge - it's quite obvious once you know what you're looking for. If the glass is smashed, look up your vehicle in our listings and the type is shown for each side.
Does wide angle glass make things look further away?
Yes, slightly - the more pronounced curve compresses the image a little more than convex. It's the same principle as convex but more noticeable. Objects in wide angle mirrors are closer than they appear, which is worth keeping in mind until you're used to it. Most drivers adjust within a day or two of driving.