Aspheric lenses with curvature changes

Unlike spherical lenses, aspheric lenses haveclear vision than traditional spherical lenses. Those
different curvatures on their front surface. It isconventional lenses have a narrower clear vision
commonly known that spherical lenses have thearea, so that vision distortion may be aroused if
same curve across their entire surface. Theyou look away from the lens center.
changes in curvature allow aspheric lenses to haveWith flatter curves, the center of an aspheric lens
flatter curves than conventional lenses, bringingfit closer to the wearer’s face. These
thinner and slimmer appearance.aspheric lenses bring both more natural external
In conventional lens types, a heavy prescriptionworld and more natural wearer’s eyes.
usually requires thick lenses to provide enoughSpherical lenses for heavy hyperopia magnify
visual correction. Those current thinner asphericboth the wearer’s eyes and the surrounding
lenses eliminate worries about thick lenses forobjects, while those conventional lenses for
people with serious vision problems. These flattermyopia minify these things. Both of these two
lenses also bring less bulging from the frame. Inopposite visual distortions bring unnatural images.
most cases, an aspheric design is combined withWhat’s worse, they result in
high-index lens materials, resulting in extremely“bug-eyed” or “beady-eyed”
slimmer, thinner and slighter lenses. Besides usualappearance.
high-index materials, regular plastics can also beAspheric lenses are now available both in single
used to manufacture aspheric lenses.vision types and multifocal types. Complex curves
Although all aspheric lenses offer a slimmeron aspheric lenses require more time and skills
appearance for every prescription, they havefrom the optician in lens measurements and
different shapes while dealing with different visionfitting, so that a higher price is reasonable. Their
problems. Aspheric lenses for myopia correctioncosmetic and visual benefits deserve a high price.
are thinnest at the center and thickest at theThe frame selection of aspheric lenses is also a
edge, while those for hyperopia correction arelittle more complex than that of spherical lenses.
thicker in the center and thinner in the edge. EvenIn addition, anti-reflective coating is nearly
if certain portions of aspheric lenses are thickernecessary for all aspheric lenses, since the closer
than other parts, they do have brought an overalldistance between the lens and the wearer’s
thickness reduction.eye brings more reflection from the lens’
Just like expensive aspheric camera lenses,front and back surfaces.
aspheric eyeglass lenses provide a wider area of