Personally I do not recommend you to buy varifocal glasses online, because it simply cannot be done due to the complex measurements that would need to be taken by a fully trained dispensing optician. However, most internet based varifocal glasses retailers cannot provide such a service as their businesses are purely based online. Most of the sales staff who work in high street optical stores are more than capable of taking varifocal measurements. The reason that these measurements are required Is because the lens technician, who makes your spectacles, has to align the centre of the varifocal so it sits in front of your pupils. If this measurement was not taken then it is highly likely that you would not be able to see through your varifocal glasses correctly.