I go to the all for $1.00 store and buy up plenty. I have one in the kitchen. 3 pair on the tables in the living area, one by my bed, one in the bathroom and of course one in my purse. Im 56 and you probably wouldnt need strong ones. try each on and read something while you are in the store. I used to buy the $15.00 ones but not anymore. these are the same.