CN105572901A - Aspheric diffraction type contact lens for correcting myopia and presbyopia - Google Patents

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

The aspherical diffractive type contact lenses of myopia correction and presbyopia

Technical field

The invention belongs to folding to spread out mixed type ophthalmic lens field, be specifically related to a kind of contact lenses with the large depth of field, can continuous print is clear to look thing scope for human eye provides, during the change of pupil size simultaneously, its property retention is stablized.

Background technology

When normal eye is in the state of nature not having to regulate, just in time imaging is on the retina for infinity object.When observing closer object, eyes produce conditioning signal automatically, ciliary muscle contraction, and lens surface curvatures radius reduces.But with advancing age, the decline of muscle regulating power, lenticular regulating power reduces gradually, thus forms presbyopia, can only to a specific range blur-free imaging.Along with the increase of China's elderly population, the rectification of presbyopia receives increasing concern, also brings very large market simultaneously.

The method of correcting presbyopia the most traditional is frame eyeglasses.General frame eyeglasses has specific diopter, and can only see the object of specific range (being generally reading distance) clearly, other distances do not see Chu.In order to overcome the deficiency of the single focus of common presbyopic glasses, the design of bifocal slasses, Progressive addition lens is in succession suggested and is applied to market.Meanwhile, be intended to for human eye provides the design of the multifocal of more areas imagings (being mostly bifocus) contact lenses and eye artificial lens to be suggested.The major defect (part can be overcome by new three multifocal design) that this kind of design exists is exactly can see clearly at a distance and 2 points nearby, and center section does not see Chu.

There is presbyopia in human eye, with advancing age, its presbyopia degree increases gradually after 40 years old.Meanwhile, China is a myopia big country, and after this part myopia population steps into old age, its eyesight also can be subject to the puzzlement of presbyopia while being subject to myopia puzzlement.This part crowd has a feature, although there is presbyopia, also there is certain adjustment force.Therefore, have the human eye of near-sighted concurrent presbyopia simultaneously for this part, the present invention devises the contact lenses that can provide continuous field depth.In addition, one of human eye and other optical systems is not significantly both, and its diaphragm (pupil) can change according to the difference of light intensity, and therefore the performance of these contact lenses keep stable when pupil size changes.

Summary of the invention

The object of the invention is to the above-mentioned deficiency overcoming existing contact lenses, the residual accommodation power of actual human eye is taken into account, a kind of aspherical diffractive type contact lenses for correcting the human eye with certain concurrent presbyopia of myopia regulated being provided, improving the optical property of contact lens eye.

Provided by the invention for the concurrent presbyopia of myopia correction, there are the aspherical diffractive type contact lenses of certain regulating power human eye simultaneously, optics comprises front surface and rear surface, described optics has large depth of field performance, can correct the intermediate range distance of the concurrent presbyopia of the myopia with certain adjustment force human eye to long-range distance and 450mm ~ infinite remote eyesight; There is diffraction ring in described optics, the short range distance of the concurrent presbyopia human eye of the myopia with certain adjustment force and the eyesight of 240mm ~ 260mm can be corrected.Described front surface radius of diffractions circle is respectively: 0.743mm, 1.057mm, 1.296mm, 1.494mm, 1.664mm, 1.815mm, 1.954mm, 2.087mm, 2.224mm, 2.409mm, 2.578mm, 2.693mm, 2.751mm, 2.794mm, 2.829mm, 2.858mm, 2.883mm, 2.906mm, 2.927mm, 2.945mm, 2.963mm, 2.979mm, 2.994mm.

Optics of the present invention has large depth of field performance, and its large depth of field performance is provided by the front surface of optics, and the face type of front surface is set to even aspheric surface, and the face type of contact lenses front surface is described as

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1-k\right)c^2{r}^2}}+a_1{r}^4+a_2{r}^6+a_3{r}^6+a_4{r}^8+a_S{r}^{10}$

Wherein, a ₁~ a ₅be followed successively by the even asphericity coefficient from 4 rank to 10 rank, c is the curvature at aspheric surface summit place, and r is that in aspheric surface, any point is to the distance of optical axis, and k is secondary circular cone coefficient.The asphericity coefficient of described front surface is: a ₁=-3.840E-003, a ₂=-1.560E-004, a ₃=-8.060E-005, a ₄=-5.170E-005, a ₅=-8.150E-006.

Described optics rear surface and eye cornea are fitted, and radius-of-curvature is consistent with anterior surface of cornea.

The basic parameter of the front surface of described aspherical diffractive type contact lenses is: the radius-of-curvature 8.11mm of front surface, and the center thickness of contact lenses is between 0.05mm ~ 0.25mm, and secondary circular cone coefficient is-17.772; Optic diameter is 6mm.

Contact lenses eyesight keeps stable with pupil change, and under different-diameter pupil, contact lens eye is all better than 0.8 for the eyesight on 450mm ~ infinite distance distance and 240mm ~ 260mm.

In order to better correct the defects of vision of presbyopia, consider that human eye has certain field range, the present invention keeps stable ± 4 ° of visual field eyesights simultaneously.

Advantage of the present invention and beneficial effect

The present invention uses Zemax optical design software, optimizes the face type of contact lenses, obtains aspherical diffractive type contact lenses.This invention has following functions and advantage:

The first, aspherical diffractive type contact lenses refer to that contact lens surface has done aspheric process, provide large depth of field performance, obtain continuous print intermediate range to long-range eyesight.

The second, aspheric surface adds diffraction ring, provides additional optical focal power, obtain short range and read eyesight.

3rd, these contact lenses can correct the presbyopia human eye with myopia.

4th, under different-diameter pupil, the eyesight of contact lens eye in 450mm ~ infinite distance distance and 240mm ~ 260mm is all better than 0.8.

5th, contact lenses optic diameter is 6mm, the needs of substantially realistic human eye.

6th, amphiblestroid central fovea of macula place have accumulated a large amount of cone cell, and its density sharply declines with the distance to central fovea.The recessed 1mm position of distance center, the density of cone cell can decline a magnitude, and this position is correspondence ± 4 ° of visual fields just.In order to the defects of vision of presbyopia better can be corrected, the present invention demonstrates ± 4 ° of visual fields on the optical property of contact lens eye, and find on ± 4 ° of visual fields modulation transfer function curve decline very little in the different object distances of different pupil, major part at spatial frequency 100c/mm place all higher than 0.4.

Accompanying drawing explanation

Fig. 1 is the side view of aspheric surface diffraction type contact lenses.

Fig. 2 is the MTF curve under 0 ° of visual field 2.8mm pupil diameter under different object distances.

Fig. 3 is the MTF curve under 0 ° of visual field 3mm pupil diameter under different object distances.

Fig. 4 is the MTF curve under 0 ° of visual field 4.5mm pupil diameter under different object distances.

Fig. 5 is the MTF curve under 0 ° of visual field 5mm pupil diameter under different object distances.

Fig. 6 is the MTF curve under 0 ° of visual field 6mm pupil diameter under different object distances.

Fig. 7 is the MTF curve under 4 ° of visual field 2.8mm pupil diameter under different object distances.

Fig. 8 is the MTF curve under 4 ° of visual field 3mm pupil diameter under different object distances.

Fig. 9 is the MTF curve under 4 ° of visual field 4.5mm pupil diameter under different object distances.

Figure 10 is the MTF curve under 4 ° of visual field 5mm pupil diameter under different object distances.

Figure 11 is the MTF curve under 4 ° of visual field 6mm pupil diameter under different object distances.

Figure 12 is the visibility curve under 0 ° of visual field 2.8mm pupil diameter under 450mm ~ infinite distance object distance, and wherein D is diopter, refers to the unit of power of lens, and during focal length 1m as lens, then the refracting power of this eyeglass is 1D diopter.Therefore different object distances can represent with diopter, i.e. 1/ object distance (m).

Figure 13 is the visibility curve under 0 ° of visual field 3mm pupil diameter under 450mm ~ infinite distance object distance and under 235mm ~ 270mm object distance.

Figure 14 is the visibility curve under 0 ° of visual field 4.5mm pupil diameter under 450mm ~ infinite distance object distance and under 235mm ~ 270mm object distance.

Figure 15 is the visibility curve under 0 ° of visual field 5mm pupil diameter under 450mm ~ infinite distance object distance and under 235mm ~ 270mm object distance.

Figure 16 is the visibility curve under 0 ° of visual field 6mm pupil diameter under 450mm ~ infinite distance object distance and under 235mm ~ 270mm object distance.

Concrete embodiment

Be described further below in conjunction with the particular content of drawings and Examples to the aspherical diffractive type contact lenses of myopia correction provided by the invention and presbyopia.

Embodiment 1

As shown in Figure 1, the side view of aspherical diffractive type contact lenses.Aspherical diffractive type contact lenses comprise anterior optic surface 1 and rear surface 2.Contact lenses entirety is axially symmetrical, and described anterior optic surface is convex aspheric surface and has diffraction ring.

By optimizing, the final design large depth of field of a realization (450mm ~ infinite distance distance) and have the aspherical diffractive type contact lenses of additional optical focal power (250mm), contact lenses front surface is set to even aspheric surface, the material selected is rigid high oxygen flow contact lens material, its exponent of refractive index is 1.432, and Abbe number is 55.15.

Its elementary structure parameter is as shown in table 1:

The basic parameter of table 1 contact lenses

The face type of aspheric surface contact lens surface can be described as:

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-\left(1-k\right)c^2{r}^2}}+a_1{r}^4+a_2{r}^6+a_3{r}^6+a_4{r}^8+a_5{r}^{10}$

Wherein, a ₁~ a ₅be followed successively by the even asphericity coefficient from 4 rank to 10 rank, c is the curvature at aspheric surface summit place, and r is that in aspheric surface, any point is to the distance of optical axis, and k is secondary circular cone coefficient.

Front surface asphericity coefficient a ₁~ a ₅, as shown in table 2:

The front surface asphericity coefficient of table 2 contact lenses

The radius of the diffraction ring of front surface, as shown in table 3:

The front surface phase coefficient of table 3 contact lenses

Side view (and vertical view) is as Fig. 1.And in phantom eye, analyze modulation transfer function (MTF) and the visual acuity (VA) of diverse location 450mm ~ infinite distance distance and 240mm ~ 260mm scope.Obtain the performance of these kind of contact lenses, as follows:

1) under 0 ° of visual field, contact lenses are under different pupil diameter, on different object distances position, and MTF curve is all very balanced.As Fig. 3 to Fig. 7, MTF curve declines slowly, at 100c/mm space periodic frequency place all higher than 0.2.

2) the human eye Snazzi degree that contact lenses obtain under different object distances under 0 ° of visual field, as Figure 13 to Figure 16, under different pupil diameter 450mm ~ infinite distance distance and 240mm ~ 260mm position on except respective location eyesight is between 0.6 to 1.0, on major part position, eyesight is all better than 1.0, obtains good rectification effect.

3) the present invention demonstrates the ± optical property of 4 ° of visual field contact lens eyes, as Fig. 8 to Figure 12, finds to decline very little in the different object distances of different pupil at ± 4 ° of modulation transfer function curves, major part at spatial frequency 100c/mm place all higher than 0.4.

To sum up, in whole object distance position 450mm ~ infinite distance distance (intermediate range is to long-range) scope and on the position of 240mm ~ 260mm (distance of distinct vision), contact lens eye all obtains good optical property, reaches the effect of the large depth of field.

Claims (7)

1. one kind for the concurrent presbyopia of myopia correction, there are the aspherical diffractive type contact lenses of certain regulating power human eye simultaneously, the optics of contact lenses comprises front surface and rear surface, described optics front surface is aspheric surface, and aspheric surface can correct the intermediate range distance of the concurrent presbyopia of the myopia with certain adjustment force human eye to long-range distance and 450mm ~ infinite remote eyesight.

2. contact lenses as claimed in claim 1, the front surface that it is characterized in that described optics exists diffraction ring, and diffraction ring can correct the short range distance of the concurrent presbyopia human eye of myopia and the eyesight of 240mm ~ 260mm that exist and have certain adjustment force.

3. contact lenses as claimed in claim 2, is characterized in that described front surface radius of diffractions circle is respectively: 0.743mm, 1.057mm, 1.296mm, 1.494mm, 1.664mm, 1.815mm, 1.954mm, 2.087mm, 2.224mm, 2.409mm, 2.578mm, 2.693mm, 2.751mm, 2.794mm, 2.829mm, 2.858mm, 2.883mm, 2.906mm, 2.927mm, 2.945mm, 2.963mm, 2.979mm, 2.994mm.

4. contact lenses as claimed in claim 1, it is characterized in that described optics has large depth of field performance, described large depth of field performance is provided by the front surface of optics, and the face type of front surface is set to even aspheric surface, and the face type of contact lenses front surface is described as

$z=\frac{{\mathrm{cr}}^2}{1+\sqrt{1-(1-k)c^2{r}^2}}+a_1{r}^4+a_2{r}^6+a_3{r}^6+a_4{r}^8+a_5{r}^{10}$

Wherein, a ₁~ a ₅be followed successively by the even asphericity coefficient from 4 rank to 10 rank, c is the curvature at aspheric surface summit place, and r is that in aspheric surface, any point is to the distance of optical axis, and k is secondary circular cone coefficient.

5. contact lenses as claimed in claim 4, is characterized in that the asphericity coefficient of described front surface is: a ₁=-3.840E-003, a ₂=-1.560E-004, a ₃=-8.060E-005, a ₄=-5.170E-005, a ₅=-8.150E-006.

6. contact lenses as claimed in claim 1, it is characterized in that described optics rear surface and eye cornea are fitted, radius-of-curvature is consistent with anterior corneal surface.

7. the contact lenses as described in any one of claim 1 ~ 6, it is characterized in that the basic parameter of the front surface of described aspherical diffractive type contact lenses is: the radius-of-curvature 8.11mm of front surface, the center thickness of contact lenses is between 0.05mm ~ 0.25mm, and secondary circular cone coefficient is-17.772.