Shai Ben Yaish

Thin spectacles for myopia, presbyopia and astigmatism insensitive vision

The aim of the presented research was to develop special spectacles capable of solving common ophthalmic problems as myopia, presbyopia and regular/irregular astigmatism. The method included adapting special all-optical extended depth of focus concept, taken from the field of digital imaging, to ophthalmology, and by that providing the required vision solutions. Special thin mask containing annular like replicated structure (thickness of the structure is less than one micron) was designed and proven to provide extended depth of focus. In this paper we present several experimental results as well as trials with volunteers. The testing included measuring the visual acuity under different illumination conditions (pupil size varied from 2 up to 4mm), as well as stereoscopy, color integrity, field of view and contrast. The results demonstrate improvements of up to 3 Diopters (for presbyopic that require the bifocal or the progressive lens solutions) for pupil sizes of 2-4mm. The approach has demonstrated improvement of more than 2 Diopters for regular as well as irregular astigmatism. The main advantage of the developed optical element is that it is very thin (less than few microns) and has low price, it has high energetic throughput and low chromatic aberrations and it operates over the full field of view while providing continuously focused image (in contrast to bifocal lenses having only 2 focused regions). The element also provides a solution for regular as well as irregular astigmatism that currently has no available treatment.

Extended depth of focus contact lenses for presbyopia

The purpose of this Letter is to design, develop, fabricate, and test in clinical trials a new (to our knowledge) type of contact lenses that provides simultaneous near and distance focused vision for presbyopic subjects, including those with up to 2.00 diopters (D) of regular/irregular astigmatism, as an alternative to multifocal contact lenses. The purpose is obtained by generating an optical pattern on the front surface of contact lenses, capable of extending the depth of focus of lenses by 3.00 D with high visual contrast. The pattern was fabricated on top of contact lenses and tested by the use of an eye simulation as well as in clinical trials. Use of the extended depth of focus contact lens enabled patients to achieve good visual acuity and contrast sensitivity for both distance and near vision without compromising the energy distribution or the visual fields.

Intraocular omni-focal lens with increased tolerance to decentration and astigmatism.

PURPOSE To measure the optical performance of an extended depth of focus (EDOF) intraocular lens (IOL), which provides an imaging solution for near, intermediate, and distance ranges, and to compare its optical performance to available bifocal IOLs with various extents of decentration and astigmatism aberrations. METHODS A special profile that performs interference principle-based focal extension is engraved on the top of a monofocal rigid IOL. An optical bench based on the L&B eye model was used to test the performance in comparison with the bifocal AcrySof ReSTOR SA60D3 lens (Alcon Laboratories Inc). RESULTS The imaging performances at near, intermediate, and distance ranges were mapped. Different decentration parameters and amount of astigmatism aberration were tested. In numerical simulations and the experimental bench, the EDOF IOL was demonstrated to have good visual acuity in near, intermediate, and distance ranges as well as reduced sensitivity to decentration of up to 0.75 mm and the capability of correcting astigmatism aberrations of up to 1.00 diopter. CONCLUSIONS Extended depth of focus technology is capable of providing clear and focused vision at near, intermediate, and distance ranges. Its high quality imaging is obtained under large decentration conditions and residual astigmatism. This capability broadens the potential use of the technology beyond its application as a simultaneous multifocal lens.

Omni-focal refractive focus correction technology as a substitute for bi/multi-focal intraocular lenses, contact lenses, and spectacles

We present novel technology for extension in depth of focus of imaging lenses for use in ophthalmic lenses correcting myopia, hyperopia with regular/irregular astigmatism and presbyopia. This technology produces continuous focus without appreciable loss of energy. It is incorporated as a coating or engraving on the surface for spectacles, contact or intraocular lenses. It was fabricated and tested in simulations and in clinical trials. From the various testing this technology seems to provide a satisfactory single-lens solution. Obtained performance is apparently better than those of existing multi/bifocal lenses and it is modular enough to provide solution to various ophthalmic applications.

Extended depth of focus intra-ocular lens: a solution for presbyopia and astigmatism

Purpose: Subjects after cataract removal and intra-ocular lens (IOL) implantation lose their accommodation capability and are left with a monofocal visual system. The IOL refraction and the precision of the surgery determine the focal distance and amount of astigmatic aberrations. We present a design, simulations and experimental bench testing of a novel, non-diffractive, non-multifocal, extended depth of focus (EDOF) technology incorporated into an IOL that allows the subject to have astigmatic and chromatic aberrations-free continuous focusing ability from 35cm to infinity as well as increased tolerance to IOL decentration. Methods: The EDOF element was engraved on a surface of a monofocal rigid IOL as a series of shallow (less than one micron deep) concentric grooves around the optical axis. These grooves create an interference pattern extending the focus from a point to a length of about one mm providing a depth of focus of 3.00D (D stands for Diopters) with negligible loss of energy at any point of the focus while significantly reducing the astigmatic aberration of the eye and that generated during the IOL implantation. The EDOF IOL was tested on an optical bench simulating the eye model. In the experimental testing we have explored the characteristics of the obtained EDOF capability, the tolerance to astigmatic aberrations and decentration. Results: The performance of the proposed IOL was tested for pupil diameters of 2 to 5mm and for various spectral illuminations. The MTF charts demonstrate uniform performance of the lens for up to 3.00D at various illumination wavelengths and pupil diameters while preserving a continuous contrast of above 25% for spatial frequencies of up to 25 cycles/mm. Capability of correcting astigmatism of up to 1.00D was measured. Conclusions: The proposed EDOF IOL technology was tested by numerical simulations as well as experimentally characterized on an optical bench. The new lens is capable of solving presbyopia and astigmatism simultaneously by providing focus extension of 3.00D under various illumination conditions, wavelengths and pupil diameters of the implanted lens without loss of energy at any of the relevant distances.

Cortical adaptation and visual enhancement.

Passive ophthalmic optic devices correct refractive defects of the eye but are not designed to employ neural adaptation processes. An extended depth of focus technology is implemented on conventional refractive devices, such as spectacles and contact lenses, and its testing is described. This technology is capable of simultaneously correcting all refractive errors, such as myopia, hyperopia, presbyopia, regular/irregular astigmatism, as well as their combinations. This is achieved by exploiting the capacity of the visual system for adaptation to contrast as well as its capability of creating a coherent continuous visual field out of discrete lines of sight.

Optical extended depth of focus lens design for children myopia control

In this paper we discuss the problem of children myopia control and how extended depth of focus ophthalmic solutions can assist in resolving this problem.

Clinical trials of interference-based extended depth of focus intra ocular lens design

In this paper we present the clinical trials performed with intra ocular lens (IOL) design having interference based extended depth of focus. The purpose of such IOL design is to allow cataract patients avoid using glasses after doing their surgery.

Non-toric extended depth of focus contact lenses for astigmatism and presbyopia correction

Purpose: Testing whether the extended depth of focus technology embedded on non-toric contact lenses is a suitable treatment for both astigmatism and presbyopia. Methods: The extended depth of focus pattern consisting of microndepth concentric grooves was engraved on a surface of a mono-focal soft contact lens. These grooves create an interference pattern extending the focus from a point to a length of about 1mm providing a 3.00D extension in the depth of focus. The extension in the depth of focus provides high quality focused imaging capabilities from near through intermediate and up to far ranges. Due to the angular symmetry of the engraved pattern the extension in the depth of focus can also resolve regular as well as irregular astigmatism aberrations. Results: The contact lens was tested on a group of 8 astigmatic and 13 subjects with presbyopia. Average correction of 0.70D for astigmatism and 1.50D for presbyopia was demonstrated. Conclusions: The extended depth of focus technology in a non-toric contact lens corrects simultaneously astigmatism and presbyopia. The proposed solution is based upon interference rather than diffraction effects and thus it is characterized by high energetic efficiency to the retina plane as well as reduced chromatic aberrations.