If you wear prescription glasses, then you need a pair of prescription computer glasses. If you have a copy of your prescription that is not expired, you don't need to have an eye test. The power of computer glasses is weaker than regular prescription glasses. Call your doctor first and ask what strength you need. If you don't know where to buy them on the high street, why not buy them online. It is much easier. Many online stores such as Firmoo offer computer glasses in quite low price and they will be shipped to your place.