Tablets Mobile-The Samsung Galaxy S4

Samsung has launched a smartphone which allows users to control its 5in (12.5cm) screen using only their eyes.

The Galaxy S4 follows on from last year's S3, a product that sold over 40 million units worldwide.

At a lavish, Broadway-themed event in New York, the company also demoed the phone's ability to take two different pictures at once.

Analysts widely regard Samsung to be the biggest challenger to Apple's dominance of mobile products.

The Galaxy S4 will be rolled out globally at the end of April.

Following the launch, shares in Samsung fell 1.7% in early trade in Seoul on Friday amid worries the market for phone upgrades was "flattening out".

The company's head of mobile communications, JK Shin said 327 mobile operatiors in 155 countries will carry the handset.

The device will be made available in two colours, white and black

In the UK, Vodafone, Three, Orange, T-Mobile and EE have all announced plans to offer the device on their networks.

Through a series of role-playing scenes, the South Korean firm demonstrated the phone's key features.

Much was made of the device's ability to be controlled without touching it.

Using "Smart pause", the user can pause a video by looking away from the screen.

Additionally, the "Smart Scroll" software analyses both the user's eyes and wrist to scroll through emails and other content.