The iPhone’s Face ID technology is great when it works, but it's frustrating when some sunglasses block it from working. There's been quite a bit of speculation as to the cause, and whether polarisation is a factor.
Why do some sunglasses not work with Face ID?
If, for example, you're wearing a pair of mid-silver or pink Ray-Ban shades, you'll find Face ID works perfectly: whether or not they are "Ray-Ban" or "Ray-Ban P" polarised lenses. However, if you switch to a blue or green pair -- again, polarised or unpolarised -- Face ID simply won't work.
The root issue is the tinting of the sunglass lenses: the Face ID sensors can't make out enough of your eyes behind the lenses.
How to make Face ID work with your shades
It's possible to make Face ID work with all pairs of sunglasses, but unfortunately not without decreasing the security of your phone.
If you visit Settings → Face ID and Passcode and toggle off Required Attention for Face ID, your phone will no longer try to see whether you're looking at the phone as it recognises you. Disabling this means that your phone can be unlocked if it's pointed at your face and you've got your eyes closed. Disabling it will also disable the "Attention-Aware Features" on your phone, such as how it controls display dimming.
In most cases this'll work -- it certainly will for Ray-Bans of all colours.
However, if your sunglasses are particularly large or obscure your face, you might need to set up an "Alternative Appearance". You can do this with Settings → Face ID and Passcode → Set Up an Alternative Appearance. Unfortunately, creating an alternative appearance alone isn't enough to make Face ID work without having to disable "Require Attention for Face ID".
Which sunglasses work with Face ID?
We've tried these out:
| Brand | Model | Works | Notes |
|---|---|---|---|
| Ray-Ban | RB3025 112/93 "Yellow Flash" | ✅ | |
| Ray-Ban | RB3025 112/Z2 "Copper Flash" | ✅ | |
| Ray-Ban | RB3025 112/19 "Green Flash Polarized" | ❌ | Too dark |
| Ray-Ban | RB3025 112/P9 "Green Flash" | ❌ | Too dark |
| Ray-Ban | RB3025 112/4D "Orange Flash Polarized" | ❌ | Too dark |
| Ray-Ban | RB3025 112/69 "Orange Flash" | ❌ | Too dark |
| Ray-Ban | RB3025 112/1Q "Cylamen Flash Polarized" | ✅ | Works in good light |
| Ray-Ban | RB3025 112/4T "Cylamen Flash" | ✅ | Works in good light |
| Ray-Ban | RB3025 112/4L "Blue Flash Polarized" | ❌ | Too dark |
| Ray-Ban | RB3025 112/17 "Blue Flash" | ❌ | Too dark |
| Ray-Ban | RB4147 601/32 "Light Grey Gradient" | ✅ | Works |
| Ray-Ban | RB4226 6052/9A "Green Polarized" | ⚠️ | Sometimes works |
| Ray-Ban | RB2132 902L "New Wayfarer" | ❌ | Too dark |
How to check if your sunglasses support Face ID
Our recommendation is that rather than disabling this feature, you shop for your shades with your iPhone, and try them out with Face ID before you buy.
Another test -- and it's rather more obscure -- is to hold your sunglasses in front of your TV's remote control when using it. If the IR signal from the control is able to pass through the lenses to your TV, then the glasses will probably work with Face ID.
Apple provide their own guidance for diagnosing Face ID issues, but don't say much about sunglasses, other than:
Face ID works with many sunglasses. If you're wearing sunglasses designed to block certain types of light, then your sunglasses might be blocking the infrared light used by the TrueDepth camera. Try using Face ID without your sunglasses.
Good luck!