hoya 1.7 eyry vs nikon lite 1.74

**mirage2k2** · 01-04-2006, 11:42 PM

I'm looking for a high index lense that provides the best vision. The nikon lite 1.74 I'm currently using has very poor off centre vision (particularly between the centre and the nose). I've heard a lot about the hoya 1.7 eyry and the 1.6 eyas. I've also heard good things about sola lenses. Please, please, can someone help.

**QDO1** · 01-05-2006, 03:53 AM

You need to have a face to face consultation with a qualifed optician. there are a lot more variables at play here than the lens make (RX, Fitting, Centration, BVD). then there is your old pair - are they set up to the optimum?

**mirage2k2** · 01-05-2006, 07:12 PM

My optician has done everything he can for me, including making several sets of lenses with different amounts of base out prism (4 - 6) - the vision quality seems to be related to the amount of prism in the lenses - more prism worse vision, less prism better vision. The problem is that I need the prism and the vision!

My optician, who has been excellent and very patient, recommends I go to CR39 for optimal vision, or go back to my old lense type, 1.8 non-aspheric glass, which did not have these problems. However, neither of us want to go down the glass route (time, expense, they chip, etc.) and CR39's would be extremely thick.

This is why I'm asking on OptiBoard, can anyone recommend a reasonable plastic solution that offers a good compromise between vision and thickness, like a 1.6 or 1.67, maybe even a non-aspheric plastic, etc.

Sorry to bother you all, but any comments would be very helpful.

**QDO1** · 01-06-2006, 03:31 AM

Originally Posted by mirage2k2

My optician has done everything he can for me, including making several sets of lenses with different amounts of base out prism (4 - 6) - the vision quality seems to be related to the amount of prism in the lenses - more prism worse vision, less prism better vision. The problem is that I need the prism and the vision!

My optician, who has been excellent and very patient, recommends I go to CR39 for optimal vision, or go back to my old lense type, 1.8 non-aspheric glass, which did not have these problems. However, neither of us want to go down the glass route (time, expense, they chip, etc.) and CR39's would be extremely thick.

This is why I'm asking on OptiBoard, can anyone recommend a reasonable plastic solution that offers a good compromise between vision and thickness, like a 1.6 or 1.67, maybe even a non-aspheric plastic, etc.

Sorry to bother you all, but any comments would be very helpful.

Hoya Eyas (plastic) 1.6 or Hoya glass 1.7 seem the way to go as the obvious (least risk comprimise), with ABBE values of 42. Aspheric/non aspheric wont be an issue, as the prism will be surfaced on to the back of the lenses. I cant tell you if the lenses are in range, as the size, frame, and prescription will determine those. Definatally have a AR coat

**Chris Ryser** · 01-06-2006, 04:52 AM

Originally Posted by mirage2k2

Please, please, can someone help.

How can anybody even give any opinion without knowing the RX ?

**mirage2k2** · 01-09-2006, 08:05 PM

rx is right +5.75, -1.00 a30, left +5.00, -1.25 a180, 5 base out prism

I am convinced my problems are due to aspheric lenses and high index material! I think best form lenses provide better off-axis vision than aspheric in high index material. I'm considering hoyas nulux ep double aspheric which has been designed to offer better off-axis vision. The fact that this double aspheric lense exists and is only available in high index tells me for sure that there IS a problem with off-axis vision in aspheric high index lenses.

**QDO1** · 01-10-2006, 02:57 AM

Originally Posted by mirage2k2

rx is right +5.75, -1.00 a30, left +5.00, -1.25 a180, 5 base out prism

I am convinced my problems are due to aspheric lenses and high index material! I think best form lenses provide better off-axis vision than aspheric in high index material. I'm considering hoyas nulux ep double aspheric which has been designed to offer better off-axis vision. The fact that this double aspheric lense exists and is only available in high index tells me for sure that there IS a problem with off-axis vision in aspheric high index lenses.

your problem is more than likley to do with ABBE value, and set up of your lenses. the aspheric lenses do improve off axis vision, but, only if your optician has surfaced the prism into them, rather than decentering them... you have a lot of issues that need to be carefully worked through, by a competent practitioner

THe fact there are bi-aspherics available in high index does not mean there is problems with other highindex aspherics, it might be only available in that material for a plethora of reasons, including limited tooling, lack of demand etc...

**mirage2k2** · 01-10-2006, 06:28 AM

Thanks for your response. The frames are fitted well by my optician. This problem is complicated, I've had it for a year and a half and had 2 different frames and about 6 different sets of lenses, from 2 different opticians - all 1.74 plastic aspheric!

You are right about the ABBE value but I think that the base out prism, which is surfaced, is a big part of the problem. The more prism, the closer to the OC the chromatic abberations start! In my left lense, which has 3 prism, I see colour seperation and blur right on the OC and it gets much worse as you move in towards the nose. In my right lense which has 1.5 prism the problem doesn't occur until I move about 5-10mm from the OC - much better. I used to have 3 prism in this lense also and that too was really bad. With 3 prism in both lenses even straight on vision directly through the OC was blurry!

The reason I think the problem is with aspheric is because my old lenses were 1.8 glass non aspheric and they were fine. The off-axis vision was not fantastic but it was easily 5 times better than these 1.74s. Since 1.8 glass and 1.74 plastic both have poor ABBE values I assumed the aspherics were the problem!

I think my options are, hoya 1.6 (higher ABBE), hoya 1.7 hilux (non aspheric - since my old non aspherics worked), or try the hoya bi aspheric - if they are really good I can tell you guys all about them!!! Thanks!

**QDO1** · 01-10-2006, 01:42 PM

bear in mind that chromatic abberation is in proportion to prescription/ABBE value. that meand the higher the (RX + prisim) the higher the chromatic abberation, the lower the ABBE value, the higher the chromattic abberation. recipie for por vision = low ABBE lens with high rx, with high prism

**mirage2k2** · 01-10-2006, 06:47 PM

Thank you very much for all your help! I'll see my optician asap, discuss the options, and go for a higher ABBE lens. I'll keep you guys posted on the outcome because I think this thread will definately be helpful in the future for others.