M3

To stop people from damaging they're eyes while on they're phones is to have at least a 10/20 minute break just so you'r eyes can have a little rest to prevent from you getting contact lenses or a pair of glasses, also 10/20 minute break will be also use full to save your credit if you are messaging to someone.

If you're driving and suddenly get a text from someone and pick up to message back, you could get in to a car accident and have serious consequences after, so to stop that you could get an app that reads out your messages for you if you got an smart phone or  you could just simply wait and message back when you stopped driving, or if someone was phoning you, you could pick up the phone and put it on speakerphone.

If police catches you using a phone while driving you will get three penalty points on your license and a fine of £60, sometimes you'r case could also go to court if you've been cough more then first two times and so you could loose your license driving.

D2

Positive: It's easier and faster sending a message rather then phoning them in, and it's safe so you know the person will receive your sent message, it also saves you time by quickly messaging them rather then phoning them and speaking them through, also it will cost you less by sending a message then speaking on the phone for a quite long time so each minute there money will be taken off they're credit.

Negative: If you don't have the persons phone number in you'r contacts or somewhere else in your phone you won't able to text that person as you don't have they're phone number, also sometimes the person might not receive the text because the message is too long or the person has sent lots of messages already so every message is taking its time to load and send, and  last is if the person is busy, they might not able to text you back and keep you waiting till they text back if it's really important. 

A second way of sending a message to the person is either by social network such as Facebook, almost everyone has Facebook now a days so you could just easily type in the persons name your looking for, find they're name and click to send a message to them and soon when they get online on Facebook they will receive the message eventually, this is also a good way of sending messages because it's free, quick and fast and you know the person will get you'r message.