Apple iOS 7 transition animations making some Phone users physically sick

Apple's iOS 7 brought several new and much needed features to the company's iPhone and iPad. But something that didn't get a lot of attention was its transition animations between the homescreen and the individual apps.

It turns out the animations might be a bigger issue than intended, since some Apple fans are claiming it literally makes them sick.

Michelle Barna, 31, is hesitant to update to the newest version of iOS because of those animations.

"I played around with iOS 7 on my girlfriend's phone and I felt nauseous," she told ABC News. "I'm a huge Apple fan and I haven't made the update yet because of it."

It's not just Barna who feels a little queasy. A message thread on Apple's forums has become a venting ground for queasy and frustrated users.

One user says "It hurts my eyes and makes me dizzy. So annoying that we can't downgrade!!!!"

Another writes, "I had severe vertigo the minute I started using my ipad with ios 7. Lost the rest of the day to it... And not happy at all. It's the transition between the apps flying in and out."

The thread was first spotted by The Verge.

People have also flocked to Twitter saying that the new iOS makes them motion sick.

Charles Oman, a former director of NASA's Sensorimotor Adaptation research Team, has studied the origins of motion sickness for over 15 years. While he's not doubting that people may feel their stomachs churn a little, he's hesitant to call it motion sickness.

"It takes a couple minutes of sustained stimulation to activate motion sickness," he said. "If it were an immersive environment, like a headset or an IMAX screen, then I can believe it, but it's a little harder to believe on the small screens."

Oman said that scientists have made a lot of progress in the field of figuring out how our brain activity leads to the feeling of motion sickness.

"We know that there's both a chemical and electrical link between neurons in the cerebellum and the brain stem," he said. "We just don't know the exact physiology of what causes people to throw up."

Barna normally isn't prone to motion sickness. "I've been on cruises no problem," she said. "I'm relatively okay on a train or a boat. It's only bad if I'm in the back of a cab. Or if I'm using iOS 7."

One of Barna's coworkers, Billy Silverman, 24, also felt ill while using iOS 7. "The transitions in older versions of iOS were a lot less jarring," he said. "iOS 7 feels like your zooming around on a roller coaster."

The new operating system has a parallax setting that users can toggle on and off. "It disables the effect where icons are floating in the background, but it doesn't seem to disable the zooming animations," said Silverman. "I never had an opinion on the animations before, but now I have a visceral dislike for them."

Apple did not respond to ABC News' request for comment.

iOS 7's animations may be associated with feeling physically ill, but it might not be entirely the animation's fault.

"Nausea can be triggered by specific smells and sights too," Oman said. "My friends at the Moscow Aviation Institute said that Pavlov also taught his dog to vomit at the sound of a bell."

Whether or not Barna's and Silverman's concerns are real motion sickness or something else entirely, they feel some relief in knowing that they weren't the only ones. "It was nuts, thinking 'Can I get motion sick just by being on a phone?'" said Barna. "It's nice to know that it wasn't in my head."

Watch an Apple video below introducing iOS 7 that demonstrates the zoom effect (mobile users: http://bit.ly/1aKMBk6):