接触镜验配技术 老视接触镜的验配 Multifocal fittingtips2.ppt

* Centre near designs are more pupil intuitive. Since the pupil becomes smaller when you read and with higher lighting environments. With this in mind, let’s now consider the effect of mis-matching the optic zone diameter to the patients pupil size. Matching the optic zone to the pupil diameter helps optimize vision performance. Where the optic zone diameter does not match the pupil size, the overall clarity of vision may be affected. In a center near design, where the pupil is smaller than the optic zone, near vision will be clearer than far as the paraxial rays from the periphery of the optic zone do not enter the pupil. Conversely where the pupil is larger than the optic zone, the overall image will be diminished by light scatter. Matching the optic zone to the pupil diameter can help optimize the visual performance of the MF lens. * * Simultaneous vision means that both distance and near prescription are found within the pupil. Alternating vision is normally used with GP design lenses that translate or move up when you read so that the bottom or peripheral near zone now moves into the pupil area and lens stays centred when you look at distance. * We are still looking for the perfect presbyopic lens! CD= centre distance, CN=centre near * Restricted launch at the moment, planned to be readily available before the end of the year. * Unique design in that as the add power increases, the BOZD of the lens reduces in size, since it assumes that the pupil size is also decreasing in size. * ? The International Association of Contact Lens Educators IACLE SPONSORS ? The International Association of Contact Lens Educators Industry Supporters Major In-Kind Supporter ? The International Association of Contact Lens Educators 多焦接触镜 王海英 L. Gina Sorbara 同时视镜片 同心圆设计 (球面) 中央视远设计 中央视远部分 (D) 视近部分(N) 渐进光学(非球面) 中央视远设计 最适合大瞳孔,在瞳孔区可同时有视远和视近部分 瞳孔小于光学区设计 瞳孔大于光学区设计 瞳孔等同光学区设计 Use for educational purposes by permission of Johnson Johnson Vision, Inc. 远视力 近视力 D D D 同时视