Wearable telescopic contact lens

Abstract

We describe the design, fabrication, and testing of a 1.6 mm thick scleral contact lens providing both 1× and 2.8× magnified vision paths, intended for use as a switchable eye-borne telescopic low-vision aid. The F/9.7 telescopic vision path uses an 8.2 mm diameter annular entrance pupil and 4 internal reflections in a polymethyl methacrylate precision optic. This gas-impermeable insert is contained inside a smooth outer casing of rigid gas-permeable polymer, which also provides achromatic correction for refraction at the curved lens face. The unmagnified F/4.1 vision path is through the central aperture of the lens, with additional transmission between the annular telescope rings to enable peripheral vision. We discuss potential solutions for providing oxygenation for an extended wear version of the lens. The prototype lenses were characterized using a scale-model human eye, and telescope functionality was confirmed in a small-scale clinical (nondispensed) demonstration.

The use of contact lenses in low vision rehabilitation: optical and therapeutic applications

“…Such devices are not successful in elderly patients with central pathology and senile pupil miosis and require a period of adaptation due to spatial disorientation that occurs; vertical movements of the contact lens eyepiece and lateral movements of the spectacle objective lens result in an apparent movement of the field and head movements induce a shift in the visual field in the opposite direction. A scleral contact lens incorporating a reflecting telescope is currently under development, which provides up to approximately three times magnification and does not require a high‐powered spectacle lens objective; however, with a total lens thickness over 1,600 µm, providing adequate corneal oxygenation during lens wear remains a design challenge.…”

Aspherical Lens Design Using Genetic Algorithm for Reducing Aberrations in Multifocal Artificial Intraocular Lens

“…As a result, more and more young people have problems with their macula luteas, causing blurred vision. The phacoscotasmus caused by macular degeneration is one of the major reasons for myopia and even blindness [6]. Apart from 3C products, some congenital symptoms can cause light to focus in advance because of the overlong axis oculi [7,8,9] and also myopia.…”

Wink-controlled polarization-switched telescopic contact lenses

“…This led to a wearable scleral contact lens with a 2.8× magnification four-reflection telescope in a 1.6 mm center thickness, where the diffractive element was replaced by a refractive achromat using a combination of polymethyl methacrylate (PMMA) and a high-index rigid gas permeable contact lens material. This lens was fabricated and used in a small-cohort clinical test [10].…”

“…The magnification could be controlled with a temple-mounted switch, but the better solution would be to offer hands-free control. This paper describes the fabrication and test of such a hands-free switching system for use with previously reported eye-borne telescopic contact lenses [10] where detailed optical design, tolerancing, and performance characterization are described. This switching system (which may also be applicable with surgically implanted telescopes) enables rapid and intuitive selection of normal and enhanced vision.…”

“…This paper is organized as follows. Section 2 describes the fabrication and characterization of the scleral contact lens telescope reported in [10], now including the orthogonal linear polarizers and retroreflector needed for switching. Section 3 details the function and component characterization of the external switching system, including the fully self-contained control electronics.…”