First, choose a reliable online optical store. Second, choose your
favorite eyeglasses frames.Third, enter your prescription. Don't forget
to enter your ADD in your prescription and choose the usage of your
glasses as computer glasses(intermediate).
It is the same as you buy other regular eyeglasses. Before you choose it, you have to make sure if need vision aids. If you need vision aids, you shall take an eye examination to get prescription. Then, you can choose a online shop through internet. And pick up a frame for computer glasses that you like, Then, input your prescription online. And continue finish your order. After pay off, you can just wait for the coming of your computer glasses.