A guide to Varifocals
Why do varifocals vary so much in price and why can they seem very expensive?
Why did I struggle to get on with Varifocal?
These are the most frequently asked questions we have in practice so it’s worth taking a moment to answer.
Varifocal lenses are a bit like cars, you can spend £500 on an old banger or £30k+ on a top of the range all singing all dancing modern vehicle.
They both perform basically the same function which is to get you from A to B so why do we see far more high end cars on the road?
Basically because a journey of any distance in a modern car is so much more pleasant an experience.
Varifocals follow a very similar principle. The more expensive lenses follow a far more sophisticated design where each section from distance through to reading is optimised to provide the maximum useable area whilst reducing such undesirable effects as swimmy vision, blurring, distortion and the like.
In general terms the more you spend on a varifocal the better the optics will be. This doesn’t mean that you have to go for the most expensive design. Often the difference between a good lens and the most expensive top of the range lens will be slight, especially on simpler prescriptions.
But the difference between a “good” lens and a basic varifocal can be huge. Both Paul and I have tried basic varifocals and found them practically unwearable with swimmy vision when walking around, tiny reading area and distortion when looking at a computer screen.
And yet people still ask for rimless photochromic all singing all dancing specs but on a budget and then can’t understand why they are less than successful.
The second reason people struggle is down to the fitting and position of the lens, in simple terms the optical centre of the lens MUST correspond exactly with the centre of the pupil both at distance and when looking down for near. Some manufacturers quote tolerances as fine as half a mm for this. So basically fitting requires that the position of the pupil is measured precisely in relation to the frame. Then lenses are ordered to match that specification and finally the lenses need to be cut precisely so that they fit in exactly the right position in the frame. Each step of that process can introduce errors that can add up to an unwearable lens / frame combination.
Even now that isn’t the end of the story as the angle that the frame makes with the face (called the pantoscopic angle) can make the difference between a wearable and unwearable combination.
Finally we have lens selection, a short corridor varifocal acts more like a traditional bifocal with large reading and distance portions at the expense of intermediate (computer) width. Conversely a long corridor varifocal will be more suited to someone who does a bit of everything like driving, laptop and reading at the expense of being particularly good at any one thing
Fitting varifocals is as much an art as a science and years of experience and the fact we do our own glazing so I am in complete charge of the process from start to finish means that I have control over all aspects of the job and can spot any potential problems before they arise.
A guide to choosing specs (part 2) One size fits all?
Not many people would wear wellies to a social function or wear high heels to do the gardening (OK I can think of one or two) You tend to wear what’s best suited to the job in hand.
In the same way you might consider different spec solutions for different situations:
Social functions Stylish, fashionable anti reflection coating on lenses Office Light, comfortable caters for correct working distance be it computer or reading. The new smart readers are excellent here
Workshop & gardening Robust, scratch resistant, some level of eye protection arms length focus
Music Arms length or beyond (3ft-6ft/1-2m) focus Shopping A good range of focus to see distance, arms length and small print on labels Working outdoors Photochromic or tint
Golf The ability to see the ball in the distance, mark a scorecard and not interfere with the swing
Fishing See a float out on the water polarised lenses score well here with the ability to tie a hook on fine line
There are many other possibilities The point is each of the above will have different priorities so whilst you don’t need half a dozen pairs of specs knowing what you are going to be (primarily) using them for is useful when considering what to have.
Safe in our hands? (Paul)
The cottage I first lived in was meant to be Roger’s retirement home and he was in the habit of popping down of an evening to do bits and bob’s of DIY and as I was invariably at a loose end I’d often muck in and help.
Upstairs previous inhabitants had been somewhat “Scottish” about throwing things away so wallpaper was layered on top of previous layers in some places 7 or 8 layers thick. You can imagine our surprise when we stripped some of this back (quite easily as they had been equally frugal with the wallpaper paste) to reveal a whole wall covered in perfectly preserved newspaper which on closer inspection turned out to be “The Times” from circa 1864 I spent several evenings perusing a veritable cornucopia of insight into a bygone age. One section in particular stuck in my memory, a cricket match
was taking place and the Times reported it thus:
"The gentlemen of England engaged the gentlemen of Australia and ably did they acquit themselves of the task…”
Score cards revealed WG Grace got a pair of spectacles and various other historic names were also present. I thought little more of this and one evening came home to find the walls cleared back to the plaster. It was only several years later when I told this story to a chum who also happened to be a cricket nut did I get an inkling of how valuable those records might have been, only twice in my life have I seen this Yorkshireman with a tear in his eye the second being when the chancellor announced a penny on a pint of beer.
Recently I was regaling some of my model flying chums with this story and one (a Nottingham uni professor) told me of Einstein’s visit to the university to lecture in the 1930’s
Evidently he covered several blackboards with equations related to his recently published theory of relativity
The plan was for the university to cover said blackboards and keep them for posterity
What’s less well known is one member of the cleaning staff, keen to impress came in early the next morning and was busy dusting the boards clean when the staff member tasked with saving the priceless archive turned up, another few minutes and it would have all been wiped away.
Recent searches do not show WG Grace ever getting a pair of spectacles
(that is a duck in both innings for the uninitiated)
which suggest that either:
(a) The Times got it wrong
(b) Wikipedia got it wrong
(c) The whisky was finally taking it’s toll on my few remaining brain cells and I read it wrong or:
(d) It turns out there were several “Graces” E.M. W.G. etc and I simply got the wrong one.
From what I can gather only one of the blackboards survived the over enthusiastic cleaner and is still on display to this day
(suitably protected by a sheet of Perspex)