First, goes against the burnt error Goes against Jiao Du is the vision rectifies lens' key parameter, its and corrects defects of vision erroneous immediate influence the degree which to the eyeglasses quality. Some match the mirror person opposite vertex burnt error to be specially sensitive, erroneous 0.25D
oakley half jacket xlj polarized can feel that ill and the vision cannot obtain the correction. This is because of the nearsightedness, The hyperopia or astigmatism match the mirror person, when observes the object, image formation after the retina or, after having one's eyes tested and wear glasses the eyeglasses, causes the object just right image formation to form the clear phantom above the retina, achieves corrects defects of vision the function.
Therefore is at the highest point time burnt error exceeding the allowed figure, is impossible Image formation above retina, also cannot serve the purpose which corrects
oakley half jacket sunglasses defects of vision, after having one's eyes tested and wear glasses, also possibly will produce dizzy disgusting, the eye bulge to hurt and so on bad reflection. Second, disperses the optical axis request Because the astigmatic lenses are use in rectifying the eye the cornea various midnight and noon direction radius of curvature to vary send, but creates various meridians diopter varies sends, through these meridian's optical fiber, cannot hand over gathers in the identical focal point ametropia. Dispersed the optical axis to stipulate astigmatism lens midnight and noon The line radius of curvature varies the direction which sends. It with matches the direction which the mirror person cornea surface meridian radius of curvature varies sends to be opposite, thus compensation astigmatism matches each optical fiber which the mirror person factor noon-mark diopter varies sends creates not to be able to focus in the ametropia which identical lights, achieves the correction Vision goal. Therefore disperses the optical axis to conform to the stipulation, otherwise it not only cannot have the compensation to match the mirror person meridian diopter to vary sends, instead intensifies the meridian diopter difference, reduces the vision. Third, pupil distance, optical center horizontal deflection and optical center vertical mutually inferior The eye faces up to the axis of the eye and between the parallel time two pupil center distance is called the
oakley half jacket xlj sunglasses pupil distance. The optical center contour interval is refers to two lens optical center in and the mirror circle geometric center segment parallel direction distance.
The optical center horizontal deflection refers to the differential value which the optical center contour interval and the pupil are apart from. The optical center altitude is the optical center and the mirror circle geometric center in the vertical direction distance. The optical center vertical mutual deviation is two lens optical center high differential value. The optical center horizontal mutual deviation is the lens optical center in the horizontal direction and eye pupil's one-sided deviation. The above several items are guarantee the eyeglasses lens optical center and the pupil center superposition, the guarantee optical
oakley half jacket polarized sunglasses system's coaxality. In the optical instrument the binocular instrument optical axis parallelism request is very strict, if not parallel will have the reflection image. But lens optical center and pupil center Does not superpose, will have the triangular prism effect, will observe the object phantom will have the displacement, will match the mirror person only then to carry on the adjustment through own adjustment function, will intensify the eye strain, if will have one's eyes tested and wear glasses for a long time, will affect the eye the adjustment function, will cause the vision to drop, serious will also occur Swiveleye.