Optical performance of progressive power lenses
(1987) Optical performance of progressive power lenses. Clinical & Experimental Optometry 70(5):pp. 149-155.
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Abstract
The off-axis powers of five types of progressive power lenses were measured on a modified vertometer. The lens types assessed were the Sola Graduate, the Hoya Varilux II, the Rodenstock Progressiv R, the American Optical Truvision, and Zeiss Gradal HS. The performance characteristics assessed were size and stability of distance and near zones, intermediate zone width, regularity of power increase in the intermediate and near zones, and distribution and axes of aberrations in the peripheral zone. None of these lenses is clearly superior or inferior to others; all have their strengths and weaknesses. Progressive lens types can be classified either as "hard" or "soft" types. Hard designs have their aberrated areas confined to smaller areas on the lens surface than do soft designs, but the rate of change of aberrations of the hard designs is greater. In lenses of soft design the aberrations extend well above the 180 degree meridian through the fitting cross. The order of decreasing "softness" of the tested lens types is Hoya Varilux II, Zeiss Gradal HS, and Sola Graduate (all classified as "soft"), Rodenstock Progressiv R and American Optical Truvision (both "hard"). This order is generally reflected by the extents of near zone sizes, intermediate zone widths and peripheral astigmatism.
| Item Type: | Journal Article |
|---|---|
| Status: | Published |
| Keywords: | aberrations; off-axis power; progressive power lenses; spectacle lenses |
| Subjects: | 320000 Medical and Health Sciences > 320900 Optometry |
| ID Code: | 4773 |
| Deposited By: | Bonham, Mark |
| Deposited On: | 15 August 2006 |
| Alternative Locations: | http://www.optometrists.asn.au/ceo |
| Copyright Owner: | Copyright 1987 Optometrists Association Australia |
| Copyright Statement: | The contents of this journal from 1998 to 2005 can be freely accessed online via the journal’s web page (see link). |
| Additional Information: | For more information or for a copy of this article contact: David A. Atchison d.atchison@qut.edu.au |