Apart from eye strain and finger strain, and the fact that using the damn thing is compulsive, watch your step!!!! I put down my laptop to answer the phone, tripped on the lead for the mouse, because I don't like the touch screen cursor and went flying! Blood all over the place, broken arm, broken leg - okay not broken arm and leg but there was blood. And there will be bruises since I landed flat out on the floor. Hoisted myself up and staggered to the phone only to hear a ship's siren and an automated voice saying - This is your captain speaking. One advantage of automated calls - you can say what you like and they can't hear you.
Oh good grief - I hope I hadn't just won a cruise.