In a recent column published in Forbes, contributor Brooke Crothers reached out to display expert Dr. Raymond Soneira of DisplayMate Technologies. Soneira told Crothers that Apple (NASDAQ:AAPL), which was once known for its class-leading smartphone displays, is "running well behind the display curve" relative to archrival Samsung (NASDAQOTH: SSNLF).

What's quite surprising is that it took just a few short years for Apple to go from selling devices with truly world-class displays to, well, not.

In 2012, iPhone 5 creamed the Galaxy S3 in DisplayMate's tests
Back in late 2012, DisplayMate posted a head-to-head comparison of the displays on Apple's iPhone 5 and the AMOLED display found on the Samsung Galaxy S3.

The results painted a dim picture for the S3. The iPhone 4's LCD scored an overall grade of A- in DisplayMate's tests, and the iPhone 5's LCD earned a solid A. In contrast, the Galaxy S3's display scored just a B+.

The iPhone 5's display was significantly brighter than Galaxy S3's, offered a higher contrast rating in high ambient light conditions, and was substantially more color accurate, to boot. The iPhone's display was also more efficient, consuming just over half the power that the S3's display did.

Back then, Tim Cook was justified in calling OLED displays "awful."

The shoe is now on the other foot
Beginning with the Galaxy Note 4, Samsung's OLED displays surpassed the LCDs on Apple's then-latest iPhones, the iPhone 6/6 Plus in DisplayMate's tests. DisplayMate called the iPhone 6/6 Plus LCDs the best LCDs that they had tested, but Samsung's Note 4 featured the best display that DisplayMate had tested, period.

The South Korean giant continued to iterate aggressively on its OLEDs, bringing significant improvements with the Galaxy S6, even more with the Note 5, and still more with the recently launched Galaxy S7 and S7 Edge.

In contrast, Apple brought virtually no improvements to the LCDs that it outfitted its latest iPhone 6s/6s Plus smartphones with. Those LCDs were competitive back in late 2014, but the relentless pace of iteration on Samsung's part means that buyers of Galaxy smartphones are now enjoying objectively better displays than those found on Apple's best iPhones.

DisplayMate says OLED is the answer
Over the long term, there's no doubt in my mind that Apple will be forced to switch to OLEDs in order to compete. There are clear benefits to good OLED displays these days over good LCDs, and it's just a matter of time before there are enough suppliers ready to produce OLEDs are in place to satisfy Apple's needs.

In the meantime, though, there's still plenty of room for Apple and its suppliers to improve LCDs. There are mobile LCDs out there that pack in more pixels than what Apple's do, ones with better color accuracy, higher contrast ratios, wider color gamuts, and so on. Even by mobile LCD standards, the panels found on the iPhone 6s/6s Plus just aren't class leading -- something that I believe may have hurt the appeal of the iPhone 6s/6s Plus to potential buyers.

With the iPhone 7/7 Plus, I expect Apple to deliver increased display resolutions on both models. In addition to sharper displays, I expect that the new panels will be more color accurate, support a wider color spectrum than typical sRGB (DCI-P3 gamut seems likely), and offer improved contrast ratios.

Such enhancements should be enough for the iPhone 7/7 Plus to remain competitive during their product cycle. Where things could get tricky is the iPhone 7s/7s product cycle.

By that time, I expect that many of Apple's competitors will have shifted to OLED displays for their premium handsets. If Apple doesn't shift to OLEDs as well at that time or, at the very least, deliver another big leap in the performance of its LCDs, then, it won't just be "behind" in display tech compared to a handful of premium flagship Android devices but a whole fleet of them. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.