Lumia 950 & 950 XL are the most recent example, but months before, we already had the Fujitsu NX F-04G (sold in Japan), the Vivo X5Pro and ZTE Grand S3 (sold in China), and other handsets that are relatively obscure to non-Asian audiences.
With that said, iris scanners are still a novelty, because only a small number of smartphones have them, and for one reason or another, none of them are widely known to global consumers. But the technology is readily available, and as is the case with even the most bulletproof components, it's up to smartphone manufacturers to make the best of them with good engineering and solid algorithms. Being big and influential brands, we don't expect Samsung and LG will ship half-baked iris scanners on their "hero" phones. At worst, we expect an experience matching that of the newest Lumia handsets, which isn't prime for replacing the fingerprint scanner (but probably good enough to supplement it in some way).
Now, let's dig a little deeper and understand what is it that gives your eyeballs their magical smartphone-unlocking abilities!
How it works
All of this complicated math is cranked out in just a second or two, which is a testament to how powerful mobile processors have become. The encryption in use is your standard asymmetric cryptography scheme, in which a pair of keys is used to encrypt and decrypt a piece of information. Also, with high-quality iris scanners, it should be only the hash code that's present on your device. No photographs or other types of easily exploitable information are meant to remain in memory, or get transmitted between servers.
The second implementation, developed by Kansas City biometrics startup EyeVerify, works in much the same vein, but omits the IR light. Technically, its Eyeprint ID method doesn't scan the iris, but the patterns of blood vessels in the sclera (the whites of the eye), as well as other micro-features. Thus, it's able to do its thing with just the smartphone's front cam, but this simplicity may warrant some unwelcome trade-offs. For example, we're not sure how good the implementation fares in challenging light conditions without the IR LED. Moreover, the Vivo X5 Pro, which uses this technology, can take up to 20 uncomfortable seconds of holding your smartphone at eye level to register the patterns, and over 5 seconds to unlock, which sounds terrible.
Samsung's and LG's plans
As for LG, we read a number of times that the company is working with fellow Korean firm Irience on developing an iris scanning module and algorithms for the upcoming LG G5. Last we heard, work on the hardware module is complete and the two are polishing the software to increase the recognition range from 12in (30cm) to a cool 20in (50cm). Irience's proprietary technology isn't fully detailed, but it has been in development for more than 15 years. Hopefully, LG and Irience have been meticulous and striving for greatness, rather than rushing towards a deadline.
Meanwhile, you should really check these out:
The user benefits
Eye recognition is non-contact, which brings forth some welcome advantages. Bearing close contact with our digits, fingerprint scanners easily get dirty and sometimes fail to function. An iris scanner is free of such problems and is also immune to the sort of tricks your children, friends, and jealous significant others can play on you — lightly touching your locked smartphone to your finger as you're asleep, and getting away with your most personal device.
However, it's going to take a while before eye scanning achieves the sheer convenience of a properly implemented fingerprint reader. The one on the Lumia 950 & 950 XL is the most advanced on the market, and at present, it's unable to stand up to fingerprint security's comfortable, refined operation. Rather than simply reaching for your phone, you must hold it against your eyes at an unnaturally close distance. Two times out of three, the scanner won't identify your stare if you're not looking at it directly, but at an angle. These shortcomings make for a significantly slower, cumbersome user experience compared to present fingerprint readers.
At present, eye scanning is no competition for the fingerprint scanner's combination of immediacy and level of security. Thus, we think a combination of both will be ideal, as you will get to decide between two advanced, strongly secure methods according to your preferences. Maybe you'd like to use the iris scanner for unlocking and the fingerprint reader to authorize payments, or vice-versa, depending on your surroundings. We're certainly looking forward to how Samsung, LG, and other manufacturers may implement and further refine eye scanning technology. If, of course, they choose to adopt it in their upcoming flagships.