Lately, it would be challenging to find someone who doesn't own some sort of smartphone. Tablets and smartphones are so handy when we're on the go. However as handheld devices have little screens, a lot of users often hold their iPads and iPhones much closer than they would hold newspapers and books. This gives way to a whole lot of visual demands that force your eyes to function in a way that's different to its normal activity.
Small text and images require your eyes to work much harder in order to focus. After some time, research shows this may cause problems with focus and vision, especially for those who already use vision correction, like glasses or lenses. If you already wear glasses, holding a device too close to your face will make it even harder for your eyes to correct for distance. Your eyes strain, and you wind up with headaches or migraines, which aren't pleasant.
In addition to this, more time looking at your small screen can reduce your blink rate, and that can lead to dry eyes and blurry vision.
In order to stop eyestrain and blurred vision resulting from the use of handheld devices, it is recommended to make the text on your device much bigger and try to keep your smart phone as far away from your eyes as you can. And don't use your phone for too much time at once! If it's been a while, let your eyes have a rest. And after that, if you still experience eyestrain, it might be time for glasses specifically made to help you focus up close. You've only got one pair of eyes. Care for them well.