Could you correct my mistakes at my essay?

Topic: Should students be allowed to use phones in elementary and high schools?

Essay: Developement of technology brought us many opportunities. Telephones are one of them. It was expensive, but nowadays, telephone usage is cheap and common. This also brings debates in its wake. Families face this question "should students be allowed to use phones in elemnentary or high schools?". I am the one who don't support usage of phones in that young ages. First, phones have dangerous lights. It may harm children's eyes. Using telephones long time cause hearing impairment. Children may hurt their wrists because of holding phones on their hands during long times. Second, they may get their phones stolen or lost. Children who are in play age may not carry this type of responsibility. In contrary some say that smartphones and communication is very important. This is very common contemporary idea. But using smartphones in young ages cause asocialization problems. To wrap it up, we can say using phones at young ages have more dominant side effects like health problems, robbery problems. Families who think to buy phones their kids must thinks cons of this topic.