Known for their sleek, lightweight design, Apple products have a reputation as user-friendly. As late CEO Steve Jobs put it: Design "is not just what it looks like and feels like. Design is how it works."
But one former employee says Apple has lost its way.
Though Apple products are "more beautiful than before," they are harder to use, technology usability consultant Bruce Tognazzini told CNBC's "Squawk Alley" on Tuesday. The former Apple employee recently spoke out in business magazine Fast Company, saying that Apple is "destroying design" by focusing on thin, low-contrast fonts.
"Steve [Jobs] was the usability testing function at Apple," Tognazzini said. "If he liked it, then it shipped. Apple lost its greatest usability person about three years ago when Jobs died. And the function was not taken over by anyone."
When Apple rolled out iOS 7, for example, it said it had refined the typography to make it cleaner and simpler. But Tognazzini pointed to iOS 7 as one of Apple's "blunders," because the fonts were too thin for many older users to read, he said.
"All they needed was one test subject to come in who was like 55 years old and sit down and say, 'Yes, I would love to do what you're asking me to do but there's nothing on the screen but pictures,' and they would have realized they had a problem," Tognazzini said.
Tognazzini said he thinks Apple should do more to go back and testing the finished products. But with shares of Apple up almost 7.5 percent this year, any impact to sales is a long way off, Tognazzini said.
"Apple's primary function is to sell products, and to that end, they are doing an absolute brilliant job," Tognazzini said. "Secondarily to that, it would be nice if these products were usable. And that's where the problem is coming in."
Apple did not immediately respond to CNBC's request for comment.