Infrared triggered smart contact lens for the treatment of presbyopia

Abstract

A switchable contact lens prototype was fabricated and tested with integrated off the shelf electronic components to drive a liquid crystal active lens element. This prototype was capable of changing its focal power by an average of +1.9D, but a maximum of +3.2 ± 0.2D was also measured. Switchable focus contact lenses are intended to help restore functional near and intermediate vision accommodation to those suffering from presbyopia, an inevitable age-related eye condition. The custom PMMA contact lens substrates used in this prototype are equivalent to commercially available scleral contact lenses. It was discovered that more careful design considerations are needed when at least one of the substrates is <100µm thick (which is needed for a final device). Without these design considerations, the switchable focal power of the lens is susceptible to change as the liquid crystal insert layer is able to flex. The prototype has an on-board electronics platform which was self-powered with a battery. Illuminating the electronics package with a 600Hz infrared signal switched the device on, which passed an AC voltage to the electrodes of the contact lens, reorientating the director of the liquid crystal with an electric field. To our knowledge, this is the first demonstration of a battery powered and wirelessly triggered smart contact lens for the treatment of presbyopia.

Toward the Next Generation Human–Machine Interaction: Headworn Wearable Devices

“…The new contact lenses will be used for biosensing and diagnosing various eye diseases. , Early research in this area of smart contact lenses used opaque and fragile components to enable the operation of electronic devices, thus obstructing the user’s line of sight and posing a potential threat to the eye. Due to user requirements for comfort and high oxygen permeability, soft lenses such as poly­(hydroxyethyl methacrylate) (PHEMA), poly­(vinyl alcohol) (PVA), polyacrylamide (PA), polyethylene terephthalate (PET), or polydimethylsiloxane (PDMS) lenses are widely used in integrated sensing technologies. − In innovative contact lens technology, light-mediated therapy has gained widespread attention as a treatment for age-related macular degeneration and other ophthalmic diseases that can ameliorate oxidative stress in retinal cells. − Figure a shows the structure of the red ILED contact lens. By embedding a circuit transparent antenna, a rectifier, and an ILED pixel in the contact lens, the user can wear the device without interfering with vision while allowing the emitted light to reach the retina for light-mediated therapy.…”

Refractive-type Varifocal Liquid-crystal Fresnel lenses for smart contacts

“…In these non-planar, oddly shaped lenses, the LC thickness is not uniform; hence it is not possible to continuously control the LC index of refraction with just one set of electrodes [41]. These lenses can only provide bifocal optical power settings (low, high) at the two extremes of the birefringence [42].…”

Ultralow Power On-the-Eye Vergence and Distance Sensing Through Differential Magnetometry

“…The emergence of smart, ocular microsystems is enabling the realization of revolutionary displays and medical devices [1]- [7]. In particular, one of the biggest and most promising medical applications of these wearables is the electro-optic restoration of sharp vision lost due to presbyopia, a condition that affects 89% of the aging population in the United States [8].…”