Accurate measurements of phase refractive index of soft contact lenses
نویسندگان
چکیده
منابع مشابه
[Measuring the refractive power of customized soft contact lenses].
PURPOSE Soft contact lenses with spherical base curves have been used for many years. The computation of the refractive powers of these lenses is easy, requiring only that one uses the lens maker equation for thick lenses. Nevertheless, for customized contact lenses, there is yet no reliable method for measuring the higher order optical aberrations. In this study we have developed in the Center...
متن کاملMethod to make accurate measurements of refractive index
One of the important parameters used in optics is the refractive index. There are different methods to measure the refractive index in the visible region. One of the techniques used to carry out these measurements uses the method of minimum deviation that suffers a ray of light when crossing a prism. Other common methods are based on the determination of the critical angle and in the Brewster a...
متن کاملThe impact of wearing single vision soft contact lenses on the peripheral refractive error
The purpose of this study was to determine the changes in the relative Aim: peripheral refractive error produced by soft single vision contact lenses in myopic schoolchildren. 27 myopic schoolchildren aged between 13 to 15 years were Methods: included in this study. The measurements of central and peripheral refraction were made only on the right eye using a Grand-Seiko WR-5100K open-field auto...
متن کاملSoft contact lenses in cases of aphakia.
The use of hydrophilic acrylates (POIYHEMA) in the composition of contact lenses was first described by Wichterle and Lim (I960). The development of a spun cast lens has taken several years. The basic technique by Wichterle has now been extended by the manufacturers, Bausch and Lomb. Whilst the low minus powers are available in more than one back curve fitting, the high minus and aphakic series...
متن کاملThe therapeutic use of soft contact lenses.
Introduction Hydroxyethylmethacrylate (HEMA) is a hydrop~ylic absorpt1ve hydrogel of good mechanical strength which can, in the dehydrated state, he la;the cut to accura'te dimensioIlls and then rehydrated to form a softconta,et Jens of excellent optical properties. Lenses intended for correction .of ametropia (usually myopia) have a water content of 30 per cent to 40 percent hut the ma:terial ...
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ژورنال
عنوان ژورنال: Optics Express
سال: 2020
ISSN: 1094-4087
DOI: 10.1364/oe.388996