FORM 2
THE PATENTS ACT, 1970
(Act 39 of 1970)
And
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
Title: Novel refractive-diffractive multifocal EDOF Intraocular Lens for
continuous vision
1, Applicant(s):
(a) Name: Biotech Vision Care Pvt. Ltd,
(b) Nationality: Indian
(c) Address: Block 1, Abhishree Corporate Park, Opp. Swagat Bungalows BRTS Stop, Bopal-Ambli Road, Ahmedabad- 380058, Gujarat, India
2, Preamble of description
The following specification particularly describes the invention and the manner in which it is to be performed.

TITLE OF INVENTION
Novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision FIELD OF INVENTION
The present invention relates to intraocular lens. More particularly, the present invention relates to intraocular lens (IOL) with extended focal depth along with multi-focality, which helps in providing adequate continuous vision for far objects to near objects with minimized glares and halos.
BACKGROUND OF THE INVENTION
A cataract is a condition that causes clouding of the lens in the eye, leading to a decrease in vision. This often develops slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and difficulty seeing at night. The majority of cataracts are related to aging, but they can also occur due to trauma, radiation exposure, or as a result of other diseases such as diabetes. If untreated for a prolonged period, it may lead to complications like increased risk of glaucoma, inflammation of the eye, and vision loss.
The invention of the intraocular lens (IOL) was a significant advancement in the treatment of cataracts. The idea for the IOL originated during the Second World War when Harold Ridley, a civilian ophthalmologist, noticed that splinters of poly methyl methacrylate (PMMA) from a shattered aircraft canopy did not cause an immune reaction when lodged in a pilot's eye. This observation led Ridley to realize that this material could be used to create artificial lenses to replace the natural lenses removed during cataract surgery. The first successful implantation of an intraocular lens was

performed by Ridley on November 29, 1949. Today, IOLs have revolutionized cataract treatment, offering a safe and effective solution to restore vision.
The natural lens of the eye is able to change its shape and focal power to focus on objects at different distances. This ability is called accommodation. However, when an eye develops a cataract the only solution to restore vision is to replace natural lens with an artificial intraocular lens. Traditionally, a monofocal intraocular lens has been used for these purpose which have a single focal point and provide good distance vision, but require the use of glasses for near and intermediate vision. Therefore, the person with implanted monofocal IOL, cannot see the objects which is beyond the limit of vision distance of the IOL (intermediate and near vision). Thus the person using this type of IOL, has to wear prescription glasses for viewing other distance objects. This is because implanted IOL has its fixed power/focal length and aperture.
But as the lifestyle changed and demand for a spectacle free solution increased, multifocal IOLs were developed. There is a need to achieve the property similar to accommodation of the natural crystalline lens. Multifocal IOLs have multiple focal points and provide good vision at different distances, but there were some drawbacks associated with these which may cause visual disturbances such as glare, halos, and reduced contrast sensitivity. These drawbacks arises from the diffractive optics profile of the lenses. An alternate solution was developed in the form of extended depth of focus intraocular lens (EDOF IOLs). The EDOF IOL, or extended range of vision IOL, is a relatively new technology in the treatment of cataract. The basic principle is to form a single-elongated focal point to enhance the depth-of-focus, on the contrary to mono-focal IOLs (in which light is focused on one single point) or Multifocal IOLs (having 2 or 3 discrete focal points).

This elongated focus is introduced to eliminate the overlapping of near and far images caused by traditional MF IOLs, thus eliminating the halo effect; ideally, these IOLs should enhance intermediate and near visual performance, while minimally affecting distance vision. EDOF IOLs provide a continuous range of focus without a clearly asymmetric IOL power distribution, avoiding the presence of secondary out-of-focus images. EDOF IOLs have a continuous range of focus and provide good vision from distance to intermediate, but may have reduced near vision, thus there is a compromise between the reduced photic phenomenon and quality of near vision.
Due to concentrated energy in different points, multifocal lenses produce good quality images at those point but fail to bridge the gap between these points, struggling to provide the functional vision in between these regions. EDOF lenses bridge those gaps but at the expanse of compromised near vision. .
Thus the present invention aims to combine those effect of an EDOF and a multifocal lens to overcome these limitations and provide a complete solution and better visual outcomes for cataract patients.
SUMMARY OF INVENTION
The present invention relates to intraocular lens. More specifically the invention relates to the intraocular lens with multifocality property combined with extended depth of focus which provides continuous vision from far distance to near distance with minimal glare and halos.

The current invention incorporates the refractive EDOF principle mentioned in our prior art US20230404742A1 in the diffiractive multifocal intraocular lens which gives it a unique feature of clear vision at far, intermediate and near distances along with the continuous vision between these regions. The present invention also eliminates the unwanted photic phenomenon like glare and halos due to its innovative design viz. overlapping of refractive zonular geometry with the diffractive rings.
The main objective of the present invention novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision is to provide multifocal extended depth of focus effect for continuous clear vision form far to near distance and providing complete spectacle independence in cataract patient after the implantation.
Another main objective of the present invention is to minimize glare and halos by neutralizing the diffraction effect of multifocal aspect with the refraction zone component having controlled spherical aberration.
Further the present invention have the 60rdegree segment design overlapped with the diffractive rings which provides balanced energy distribution along with concentrated energy at far, intermediate and near points without compromising continuous vision even at larger pupil diameter.
Another main objective of the present invention is to minimize glares and halos by providing controlled spherical aberration.

Yet other objective of the present invention refractive-diffractive multifocal EDOF intraocular (IOL) lens is the optimized energy distribution in each annular zone to maintain good contrast irrespective of the pupil size and irrespective of the light conditions.
Another objective of the present invention refractive-diffractive multifocal EDOF intraocular lens is to reduce the thickness of the IOL, which helps in gently unfolding the lens during implantation through small incision.
BRIEF DESCRIPTION OF DRAWINGS OF INVENTION
The sketches illustrate the various embodiments of the present disclosure. The sketches are not scaled but represent exactly similar elements.
Figure 1 shows the Schematic of the refractive-diffractive multifocal EDOF intraocular lens with two different aspects namely diffractive and refractive EDOF profile.
Figure 2 illustrates the embodiment of system used for multifocality, the detailed schematic of diffractive aspect.
Figure 3 shows the schematic cross sectional view of diffractive pattern profile used to generate multiple focal points.

Figure 4 illustrates the embodiment of system used for extended depth of focus with detailed zonal power distribution mappedby different patterns.
Figure 5 illustrates the anterior surface of system with overlapped aspects of diffractive and refractive profile.
Figure 6 illustrates the side view of the invention with an enlarged view showing the square edge.
Figure 7 illustrates the zonal segmented view of the invention which have varying refractive powers with overlapped diffractive pattern.
Figure 8 shows a perspective view of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following paragraph describes the Novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision and its advantages. The subject matter is explained with drawings at required places, where in like reference numerals are used.

The current invention relates to extended depth of focus (EDOF) incorporated into multifocal intraocular lens which creates a novel design to provide clear and continuous vision from far to near distances providing complete spectacle independence with minimized glare and halos.
The current invention (10) as shown in Fig. 1 has two aspects embedded into it
1. Multifocality due to diffractive-refractive optics (20) as shown in detail in Fig.2 and
2. Extended depth of focus due to controlled spherical aberration in zonuler geometry of refractive optics (40) as shown in detail in Fig. 4.
The refractive EDOF zonular geometry is shown by highlighted boundaries in Fig. 1 having four zones (101, 102, 103 & 104). The diffractive profile (105) have been superimposed onto this zonal geometry. The outer peripheral circular zone 106 in fig. 1 is designed to reduce the center thickness of the lens and unfold the lens very gently through a small incision during implantation to the patient. Modified C type haptics (107) are designed to provide maximum contact angle with the capsular bag to provide the rotational stability of the IOL.
The multifocal aspect in the current invention is based on diffraction property of light. Considering the wave nature of light, when two similar waves emanates from a single source they interfere constructively and destructively at different points which are referred to as diffraction orders. The effects of diffractive multifocal lens can be understood by looking at the working principle of a diffraction grating. The grating is an array of linear groves created on a glass surface, when light passes through these

grooves, it split into multiple sources and light from these sources interfere with each other creating multiple points of bright and dark points known as diffraction order at different angles. To concentrate the light in 2-3 orders the design of the grooves can be modified into triangular shape also known as blazed grating, which restricts the light into two or three orders of concentrated energy. Further these grooves are modified, by changing the spacing between the diffractive zones to become progressively closer together towards the edge, which gives a focusing effect. A diffractive multifocal lens is the two-dimensional rotationally symmetric analogue to the linear gratings, where the diffractive pattern has the triangular shape as described above superimposed on a refractive base lens, so the incoming light is predominantly focuses into two or more points.
The current invention uses this property and have apodized diffractive ring pattern (20) as shown in figure 2. The center optic (2010 is 1.17 mm in radius after which the first step of diffractive pattern starts which continues with varied spacing as we go towards the periphery (202, 203) to have multiple focal points with balanced energy for far, intermediate and near vision as shown in Figure 2. The outer peripheral zone (204) is purely refractive in nature. Figure 3 shows pattern of the diffractive surface with two type of step heights as shown in the part number (301 & 303) for near and part (302) provide intermediate focal points. Every two near diffractive rings, one intermediate diffractive ring is incorporated to produces two focal points along with.the distance focal point with balanced energy distribution between them.
The Refractive EDOF property is achieved based on the principle of refraction. Fig. 4 showcases the anterior surface design of the refractive EDOF aspect of the lens with different pattern denoting the variable power in different segments of the design. The

zonal segmented design is developed to achieve extended depth of focus with minimal photic phenomenon. This has been done by engineering the power variation with controlled spherical aberrations. Spherical aberrations, normally an unwanted phenomenon in optics refers to the situation when the incoming light rays end up focusing at different points after passing through a spherical surface. Light rays passing through a lens near its horizontal axis are refracted less than rays closer to the edge or periphery of the lens and as a result, end up in different spots across the optic axis. This results in decreased quality of images (blurring). Positive spherical aberration arises when rays in periphery or marginal rays refract more and focus near by the lens, whereas in case of negative spherical aberration marginal rays focus far from the lens. Combining these two types of aberrations create an elongated focus point. But creating these aberration will also mean that quality image is compromised. To have an elongated focus without a significant decline in the quality of image, power variations along with these aberrations given which produces controlled spherical aberrations and produce an elongated depth of focus which gives a good quality image.
The EDOF surface have four concentric annular refractive zones (401, 402, 403 & 404) with three different refractive powers represented by the different pattern map, in the clear optic portion as shown in the fig. 4(a & b) and the first two concentric circular zones (401,402) having a slight power difference between them to increase the depth of field of the nominal power in fig 4(a), The first zone (401) having the negative spherical aberration and second zone (402) having positive spherical aberration. The third annular zone (403) divided into six segments with 60-degree arc length to make the nominal power independent from the pupil size, the boundaries of a single segment (405) is also shown in figure 4(a). According to fig.4 (b), third zone (403) contains six segments (410, 420, 430, 440, 450 & 460) having the power of the first (401) and second zones (402) alternatively with the negative spherical aberration of the average

power of two zones. The fourth Zone (404) as in fig. 4(a & b) contains the different power with positive spherical aberration to improve the quality of nominal power and provide the extended depth of filed without any halos and glares in scotopic light condition. The zones powers and spherical aberrations can vary as per the required depth of focus.
The two aspects (20, 40) explained above are superimposed on each other (50) as shown in figure 5, to create a unique combination of refractive diffractive principle which achieves the advantages of both aspects while cancelling the undesired effects . of each aspect. Elongated depth of focus arising through refractive EDOF surface are elevated through diffractive profile by concentration of energy at particular focus while photic phenomenon of diffractive surface are neutralized through extended depth of focus of refractive surface. Figure 6. Shows the posterior surface (601), an aspheric surface with negative spherical aberration and have the 360-degree square edge (602) as shown in enlarged view in Fig. 6 to prevent the early PCO (Posterior Capsular Opacification).The square edge prevents the movement of endothelial cells between the posterior surface and the capsular bag by helping in proper shrinkage of capsular bag around the posterior surface. Proper shrinkage of TOL with the capsular bag can prevent the early rotation of the IOL and provide good rotational stability. It will provide good effective lens position and reduction of the Dysphotopsia also controlling the PCO.
The segmented view of the invention is shown in Fig. 7 to help in understanding the zonal power distribution with diffractive pattern. First part (701) shows the center optic, the second part (702) is the trefoil designed to have three segments of third zone with similar power to the second zone. Third part (703) is the remaining three segments

of the third zone with similar power to the central zone (701). Fourth part (704) represents the fourth and final zone of the optic portion of the invention. The outer periphery (705) have the negative curvature to decrease the thickness for easy unfolding of the lens during implantation,
The clear optic (801) in the perspective view is shown in Figure 8 with both of the multifocal and EDOF aspects of the embodiments combined.
Specifications of the present invention:
Optical Material: Hydrophobic or Hydrophilic material or similar biocompatible and implantable material.
Refractive Index; 1.40-1.6
Optic Surface: Aspheric
Optical Size of the IOL: 4 to 7 mm (variable according to requirement)
Overall size of the IOL: 10 to 14 mm (variable according to requirement)
Number of concentric refractive circular zones in the clear optic area: 4 (variable according to requirement).
Number of diffractive rings: 19 (variable according to requirement).

I/We claim:
1. A novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous
vision comprises of:
An optic containing a unique clear optic with diffractive multifocal aspect and refractive EDOF aspect superposed on each other.
A haptic portion made in a single piece with the optic.
2. The novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein the invention will provide clear and continuous vision from far to near distances along with the intermediate vision for daily activities.
3. The novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein the diffractive aspect of the optic produces multifocal profile and can be designed to have two, three or more focal points with balanced energy distribution.
4. The novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein the refractive aspect of the optic comprising of annular zonal geometry with different power distribution along with the asphericity to produce extended depth of focus.
5. The novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein the four refractive zones with two different add powers of diffractive rings are given controlled spherical

aberrations to minimize glares and halos and control unwanted photic phenomena.
6. The novel refractivc-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein the third zone contains 60-degree segments along with the diffractive rings designed to provide the balanced energy distribution without compromising the depth of focus at larger pupil diameter like scotopic condition along with continuous vision.
7. The novel refractive-diffractive multifocal EDOF Intraocular Lens for continuous vision as claimed in claim 1, wherein, six 60 degree segments along with the diffractive rings in the third zone are given two alternative powers of first and second zone with controlled spherical aberration to balance the light distribution and maintaining the depth of focus along with the image quality and contrast at any pupil size or light condition.