Re: DIY Optician

Not an approach I'd considered, I must admit. The appeal of the ones in the link of course is that they seem to be continuously variable: I can see that being useful.

Could be interesting. But I can't find any reviews.

A multi element lens is not going to be ideal for specs.

bet they aren't very durable either

tim

not an option for people with short sight

I have varifocals plus a proper set of single prescription lenses set up for computer use. I add to these clip-ons at +1.5 and +3 diopter for reading small text and for close-up work.

eg eBay item 172952541377

Being a bit nerdy I would worry not only about astigmatism but other aberrations in things like this.

IIRC they showed something similar on tomorrows world a long time ago.

They have also been suggested for third world countries too, using cheap syringes for the fluid.

They were initially designed for third world countries. I cam across them 6 or 7 years ago.

I didn't know you had been to Ireland.

"fully adjustable (-6D to + 3D)"

Yeah, they are nothing new.

Third world countries now have testing/glazing centres though, where they can get an eye exam and a 'proper' pair of glasses made.

These adjustable ones are handy to replace ready readers I suppose.

dennis@home wrote on 27/08/2019 :

I remember those!

Do these use a liquid lens?

R D S was thinking very hard :

Seems simpler and much cheaper to just carry a spare pair of readers of the correct diopter.

Always blame the varifocals if you fall down some pub steps when pissed up.

The one thing that I have never really got used to with my varifocals are the cut and cornered paving slabs in shopping precincts that rise and fall in height for disabled access to buildings.

What do you for dirt between the lens?

I think these don't have fluid - in fact I was looking for variable glasses some time ago, and nobody makes that type. These glasses have two sliding lenses giving different strengths depending on sideways separation. However it can't really be done because the horizontal power will not be the same as the vertical power, resulting in astigmatism, but seemingly not noticeable judging by the glowing reviews.

One of the reviews said don't use them on the beach because the sand gets between the lenses.

Some people must

No, they have two rather complex lenses that slide over each other. The final picture on the website shows how they work. Quite clever, but I'd have thought there's a lot of distortion.