iPhone 7 is rumored to carry the same design as its predecessor, iPhone 6s. However, with regard to iPhone 8, a complete design is expected as Apple is suspected to switch to OLED display technology. In addition, it is suggested that Apple's 2017 iPhone line will be released in three sizes.

Apple is reportedly going to release a premium curved screen at 5.5 inches or larger with a screen bent on two sides, Nikkei reported. The said iPhone is believed to be a rival to Samsung Galaxy S7 Edge. The largest iPhone edition is expected to be the only device that will carry an OLED screen.

The other two models with 4.7-inch and 5.5-inch screens, on the other hand, are suggested to carry LCD displays similar to the current iPhone 6s and iPhone 6s Plus. Apple is reportedly planning to continue selling iPhones with LCD displays along with OLED because the company believes that it may be difficult to secure enough panels for the more than 200 million iPhones that are being shipped globally every year.

Meanwhile, KGI Securities analyst, Ming-Chi Kuo's who has been known to be a reliable analyst, believes that Apple's premium iPhone 8 will sport a 5.8-inch screen display, iDigitalTimes reported. He also added that Apple will be releasing an iPhone with a glass casing and wireless charging technology. The body of the iPhone, according to Kuo, will be made with metal sides like the iPhone 4's.

In the past, Kuo already claimed that Apple's shift to OLED will not happen until at least 2019. However, he has changed his statement and believes that Apple is going to launch an iPhone with OLED display in 2017.

iPhone 8's OLED display is expected to extend over the edges of the device which would stretch the screen over the existing volume, ringer and power buttons. Apple reportedly calls these virtual buttons in a patent describing the technology.