I know there a few opticians on here and i guess some people may have experience.

I know my prescription has changed since last time i got some glasses and i guess that means it is time for some new lenses. As my eyes are around the -6 level i guess that the higher index thin type lenses might be a worthwhile option.

Question is are they? sounds like a good idea, thin light lenses, but are there any downsides i should be aware of? Also coatings, do they really make a difference, i have always used them but never really thought about whether they actually offer any benefit.

I’ve gone plastic now. Even with the thin lenses the glass ones were getting heavy. Much better. Plastic does need a coating to protect it though.

I’m similar prescription. High index means I can have the specs I want without them getting hugely thick at the edges and looking silly. My prescription hasn’t changed in years though and I do have specs sitting around basically unusable as the coatings are wearing off in patches. I must get around to cleaning it all off with an etch compound and getting them re polished.

My prescription is around 3 and I went for the mildest of Specsavers three ‘thin and light’ lenses. They are about 25% thinner at the edge but the biggest and unexpected benefit is the lenses are a lot lighter so I don’t get a red nose/specs sliding down my nose all the time.

Also they look better as my old lenses had a sandblasted type edge to the lenses which made them noticeable, the thin and light ones have a polished edge.

Higher index will make the lens thinner and lighter, optically there is no difference between high index and standard cr39, coatings allow more light to pass thru the lens in theory giving slightly better vision

Something most opticians wont think to ask you, do you wear you glasses cycling if so maybe go for a polycarbonate lens as it has a higher refractive index(1.59) than standard plastic(1.5) although not quite as high is the high index(1.6-1.74) stuff if yo go this route do get a multi coat as poly does scratch more easily and the multi coat includes an anti scratch layer.

Having said all of the above the frame choice can also have a big impact on the weight/cosmetic result of the lens so speak to someone in practice for best advice

I have both plastic and glass very high index lenses and the main thing I notice is colour separation particularly with red and blue. My prescription is somewhat stronger than yours (ie nearly double).

well i think i know what design i want, just got to find an optician i like and who stocks them.

Oakley Transistor, or similar. so smallish lens and half frame. and thin wire. Alternative is reglaze my Lindberg Air rims, but fancy a change after 10 years.

The higher inde you go for the more the material will disperse the light ie split it into its separate colours. It is more of a problem with high index glass lenses rather than plastic, so you should be fine. Also -6 ain’t that high!!

One thing to be careful of is Aspheric high index lenses as you may notice some peripheral blur if you’ve been used to spherical lenses.

Modern high index plastic lenses are great, with the right frame choice ( not too big) the lenses will look thin with a 1.67 index, thinnest of all would be a 1.74 index

aP, you are close to a -12 prescription?
I’m -4.5 in one eye and cannot see my hand clearly at arms length, what can you actually see without glasses?
Not having a go, just curious.
Ta
Alan.

Errrr…. Yes -11.
Clear focus? Quite close, I’ll leave it at that.
*-*

Aye, at night I read books with my glasses off, my nose is virtually touching the page. (-7.5)

If I go to the swimming baths I lose everyone and can’t find the mens changing rooms if I’m not familiar with the place. It’d be a good excuse to wander into the ladies changing rooms ‘by accident’ although I’d not be able to see anything if I did.

Yes, that’s always good excuse. I understand that once you’ve accidentally wandered in, leaving using the universal language of touch is the established way of doing it.

It’d be a good excuse to wander into the ladies changing rooms ‘by accident’ although I’d not be able to see anything if I did.

Yes, navigating by touch is always good, just say you’re using Braille… 😀
Multi-layer AR coatings, which give the green ‘bloom’ to lenses, are really worth the little bit extra cost added to the price.

My prescription is -6.5 and when I got my last pair of specs I went for the highest index lenses available. However, they made me feel horribly dizzy. The optician told me that some people can’t tolerate very high index lenses. They replaced them with less high index ones and they are fine, and don’t look too thick!

My prescription is -6.5 and when I got my last pair of specs I went for the highest index lenses available. However, they made me feel horribly dizzy. The optician told me that some people can’t tolerate very high index lenses. They replaced them with less high index ones and they are fine, and don’t look too thick!

i thought i had heard this somewhere. I guess there is no way of knowing without trying though.

My thoughts are on that are that your optician isn’t very good.

In a similar vein, my last optician, who sadly moved on (to another practise), was a very sexy older lady. She had an astounding body, always wore very tight dresses and flirted shamelessly. She was great.

My thoughts are on that are that your optician isn’t very good.

Why? its a known issue called ‘power rings’ the optom resolved the problem, sounds like he got good service to me

If its such a well known problem, why would they have sold lenses that wouldn’t be appropriate to someone who didn’t need them? In my world, that’s not very good.

les than 5% of people will have this problem, the patient wanted the best possible cosmetic appearance of his glasses this was supplied, he had a problem they rectified it (hopefully at no extra charge) where is the bad part of the service?

I am now at -8.25 and -8.75 and I use high index lenses in Oakley frames.
They are still fairly thick on the edges but I haven’t got a choice.
I have been wearing contact lenses for over 20years and wouldn’t ride without them.
I am far too scared of falling off and breaking or losing them. Without them, no chance of getting home.
I ended up buying them online as Specsavers and Vision Express wanted more than £300 for the lenses only and of course they do not qualify for the buy one get one free/half price…
I think the online retailer was lensway, at the time, £160 with the frame, delivered.

seb is that single vision or a varifocal? just interested as £300 for SV is a ridiculous amount, for a vari it would depend on the manufacturer but could still range anywhere from a good price to expensive

Why would internal reflections within a high index lens cause dizziness?
My thoughts would be that only reason you’d get these would be due to poor lens manufacture, rather than any specific property of the lens material.
Seeing as I have a worse prescription than pretty much anyone on here and my very high index bi-aspheric lenses don’t cause me any problems, I might be in a better position to actually comment on them. So don’t patronise me.
Actually the worst issue I’ve found recently is for the fashion to have the edges polished rather than left ground.

The hustler, this was for standard lenses without any coating.
They told me with this level of prescription, glass would be better than resin as it doesn’t absorb as much light.

TBH glass is still the best material optically for lenses for both light transfer and thinness (RI of 1.9 against the best plastics of 1.74)

Why would internal reflections within a high index lens cause dizziness?
My thoughts would be that only reason you’d get these would be due to poor lens manufacture, rather than any specific property of the lens material.
Seeing as I have a worse prescription than pretty much anyone on here and my very high index bi-aspheric lenses don’t cause me any problems, I might be in a better position to actually comment on them. So don’t patronise me.
Actually the worst issue I’ve found recently is for the fashion to have the edges polished rather than left ground.

some people just cant tolerate it in the same way some people just cant tolerate varifocals due to the distortions you get in the lens, I wasn’t patronising you its just how it is and AP unless you are -21 or higher then trust me I know what i am talking about, we have patients who have to have blended lenticular lenses etc (look look a minatue version of the bullnose glass you used to see in doors)

And yes i agree v high prescriptions should not be machine bevelled as this creates a horrible ‘lightring’ affect which is both crap to look at and thru but….a well done hand bevel can take the sharp edge off the lens without the problem