Aspheric diffraction type contact lens for correcting myopia and presbyopia

A contact lens, a technology for correcting myopia, applied in glasses/goggles, optics, instruments, etc., to solve problems such as unclear vision

Active Publication Date: 2016-05-11
NANKAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main defect of this type of design (some of which can be overcome by the new trifocal design) is that the two points in the distance and the near can be seen clearly, and the middle part cannot be seen clearly.

Method used

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  • Aspheric diffraction type contact lens for correcting myopia and presbyopia
  • Aspheric diffraction type contact lens for correcting myopia and presbyopia
  • Aspheric diffraction type contact lens for correcting myopia and presbyopia

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Such as figure 1 Shown is a side view of an aspheric diffractive contact lens. The aspheric diffractive contact lens includes an optic front surface 1 and a back surface 2 . The whole contact lens is axially symmetrical, and the front surface of the optical part is a convex aspherical surface with a diffraction ring attached.

[0042] Through optimization, an aspheric diffractive contact lens with large depth of field (450mm-infinity distance) and additional power (250mm) was finally designed. The front surface of the contact lens was set as an even-order aspheric surface. Rigid high oxygen permeability contact lens material, its refractive index is 1.432 and Abbe number is 55.15.

[0043] Its basic structural parameters are shown in Table 1:

[0044] Table 1 Basic parameters of contact lenses

[0045]

[0046] The surface profile of an aspheric contact lens can be described as:

[0047] z = cr ...

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PUM

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Abstract

The invention discloses an aspheric diffraction type contact lens which is used for correcting myopia and presbyopia and has a certain eye regulation function. The diameter of the optical part of the contact lens is 6 mm, the front surface of the contact lens is an axial symmetry type convex aspheric surface, and a diffraction ring used for providing additional diopter is arranged on the front surface. The rear surface of the contact lens is attached to the cornea of people, and the radius of curvature is consistent with that of the anterior corneal surface. After the contact lens is put on, clear imaging can be achieved within the range from medium-range distance to long-range distance (450 mm-infinite distance) and near the read range (240 mm-260 mm) in a field of view which is +/-4 degrees. Furthermore, the contact lens also has the advantages that the extended depth of field is large, and vision stays stable along with pupil change.

Description

technical field [0001] The invention belongs to the field of refraction-diffraction hybrid ophthalmic lenses, and in particular relates to a contact lens with a large depth of field, which can provide the human eye with a continuous and clear range of vision and maintain stable performance when the size of the pupil changes. Background technique [0002] When normal human eyes are in a natural state without adjustment, objects at infinity are just imaged on the retina. When observing a close object, the eye automatically generates an accommodation signal, the ciliary muscle contracts, and the radius of curvature of the lens surface decreases. However, with age, the muscle adjustment ability declines, and the adjustment ability of the lens gradually decreases, thus forming presbyopia, which can only clearly image a specific distance. With the increase of the elderly population in our country, the correction of presbyopia has received more and more attention, and it has also ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02C7/04G02C7/06
CPCG02C7/044
Inventor 刘永基姜来王晓琳王肇圻
Owner NANKAI UNIV
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