Hi All!
Anyone using single vision bi-aspheric lenses?
Love some feedback
Thanks!
Alan:cheers:
Hi All!
Anyone using single vision bi-aspheric lenses?
Love some feedback
Thanks!
Alan:cheers:
Hi!
35 views and no comments!
Have I asked an odd question?
Alan
Are you talking about atoric lenses?
We've used the Hoya LX which is supposed to be biaspheric, I was quite disappointed actually. We used it to try and get a thinner result for a high plus, it wasn't any thinner than a nulux.
'
steff
How do you surface aspheric on the back ?
Freeform?
Sorry, I should have specified - I don't actually do it. Hoya Japan does them for us - 3-4 week turn around ex Japan.
steff
Hi I have worn bi-aspheric lenses my self and they are great, I have tried one by hoya and one from nikon, they are both really good as there is far less distortion at the edge of the lens, my Rx is moderate minus with moderate cyls.
Bi aspheric lenses are lenses that works a more detailed function of aspheric lenses.
Aspheric lenses has 2 main advantages.
1. Reduction of lens mass by flatting the lens curvatures. With a flatter lens curvature, lens mass is reduced and therefore the overall appearance looks thinner and lighter.
2. In spherical lenses, we require best form lenses to improve our peripheral vision through a very curved lens shape.(Correction of oblique astigmatism) However, such best form lenses are ugly and heavy, with plenty of distortions. Aspheric lenses aims to correct oblique astigmatism by incorporating astigmatism correction on its lens surface which is flatter instead.(Sounds illogical but true)
1 problem of aspheric lens is that the correction of oblique astigmatism can only be corrected at either the spherical or cylindrical meridian due to its conventional roller method. Such technology generate a uniform spherical curve with a aspheric front surface. Furthermore, aspheric range of powers are inter-used between other powers.
Bi-aspheric lenses on the other hand are created using freeform technology meaning to say a point cutter that could generate any forms of curve on the lens surface. Such lenses are truly customised to produce abberation-free rays of light to the eye with exceptional performance at both central and peripheral vision. I know of one company in Singapore that produces such a technology-based lenses and is actively marketting the product to the end-consumers. The company's name is ILT. The product name is FUTURE-X Xtreme.
Advantages-
Less off-axis power error and oblique astigmatism- much less when there is a substantial refractive astigmatism.
Slightly thinner and lighter minus lenses.
Disadvantages-
Minus powers only due to casting and/or molds.
Prime example- Sola/Zeiss 1.66 Vizio. Optima 1.66 in some powers. Outside of the US- 1.74 from Essilor is available with a bi-aspheric/atoric surfaces. Hoya and other companies may have similar designs also.
Hope this helps
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks