A frequently asked question within the busy practice is 'Why are some varifocals more expensive than others ?'. The simple answer to that question is that they are not all the same. That is something difficult
to grasp especially when one lens mounted in a spectacle frame looks much like another. The difference however is in the design of the lens and more importantly the performance of that lens for the wearer. .The spectacle wearing public I find are not particularly interested in the design of lenses (and this can be a complex subject) - they are however very interested in how the lens performs.
The two images above are a simplification of how different lens designs affect visual performance. All varifocals posses an element of distortion which manufacturers strive to minimise. These are generally situated in the inferior temporal and nasal areas of the lens as depicted above. However if you look at the 'standard' varifocal compare the width of the intermediate(top of steering wheel) and the reading (speedo). Now compare the 'premium' varifocal in the same areas - these lenses are as different as chalk and cheese but would look the same in the chosen frame.
As a rule of thumb choose the best lens you can comfortably afford. If in doubt seek the advice of the qualified Dispensing Optician in the practice. Always beware of 2 for 1 offers as these invariably are generally(but not always) going to be standard. Finally if you have worn a premium lens in the past do not go down to a standard lens design - you are very likely going to be disappointed with the results !!. This article is intended to aid patients in varifocal choices generally. It does not endorse one manufacturers lens over another - ask in practice which is best suited to your individual requirements.