Exciting developments are happening in the field of augmented reality, such as the superimposition of digital information by contact lenses. The huge interest in smart contact lenses over the past three years can mainly be ascribed to the rise in the demand for lightweight and wearable augmented reality (AR) devices, as well as the need for continuous monitoring of certain chronic medical conditions.
Several smart contact lenses are in development that will be able to display health information and other relevant information such as navigation, weather and points of interest in true AR style. Until now one of the major problems with smart contact lenses has been the wearability. The first generations of smart contact lenses were made from thick and rigid plastic, which made them very uncomfortable to wear. Fortunately, the technology has progressed and researchers from multiple fields such as biomedical engineering, optometry, ophthalmology, optical physics and nanotechnology collaborated and developed a new generation of soft smart lenses.
At Purdue University, researchers developed a thin sensor technology that uses a flexible strip of gold to conduct trace amounts of electricity in the soft hydrogel lens. Even with the smart technology embedded, these lenses could be worn for up to 30 days. The main purpose of these enhanced lenses is to provide medical care professionals with a means to better manage and monitor their patients’ eye health. Scientists at the South Korean Ulsan National Institute of Science and Technology created smart contact lenses that track the glucose levels of the wearer and provide real-time feedback to the user through a contact lens display. The team manufactured the soft lenses from transparent and stretchable nano-structures and fitted it with integrated glucose sensors, wireless power transfer circuits and displays. Although only tested on rabbits, commercial availability will significantly improve the management of diabetes and especially diabetic retinopathy.
Google has been involved in contact lens research since 2015 and also developed a set of lenses that measure the glucose levels of the user. The research engine formed a partnership with the pharmaceutical company Novartis to develop smart contact lenses that track diabetes levels by continuously measuring the glucose concentration in the tears of the wearer. This is achieved using an enzymatic sensor directly connected to miniaturised electronic circuits. The lenses also fix farsightedness or hyperopia. However, researchers are not sure yet if the glucose levels found in tears are comparable to those found in blood.
Contact lenses that track physiological parameters of the user through a wireless chip and miniaturised sensor are a major innovation in biomedicine since it entails a non-evasive medical diagnostic methodology. For instance, 67 million people in the world suffer from Glaucoma or elevated pressure inside the eye – an eye disease that can damage the optic nerve and is the second leading cause of irreversible vision loss and blindness.
Smart contact lenses that track the intra-ocular pressure (IOP) and provide real-time pressure readings would assist ophthalmologists to improve their diagnosis and treatment. Sensimed Triggerfish has developed a contact lens that monitors the IOP of glaucoma patients. The lens is currently approved in Japan and the US. It would also be possible for wearers to gain instant information on cholesterol and sodium levels, heart rate and other important measurements. As technology develops, the medical possibilities are practically endless.
In 2018 Theraoptix received the MIT Sloan Healthcare Innovation Prize for their innovative contact lens. What makes this lens unique is that it delivers eye medication in a sustained and controlled release. The lens is fitted between drug-filled polymer contact lens films that are shaped into a tiny circular strip that does not interfere with the wearer’s vision. The sandwich structure allows the drugs to slowly trickle from the film into the eye.
Samsung, the multinational conglomerate, has been involved in contact lens research since 2016. It started contact lens development as a means to create a better AR experience than the other wearables on the market. Its contact lenses have a miniscule display, built-in camera and antenna and are capable of superimposing the virtual over the real world. The user controls the sensors by blinking or other eye movement routines.
The French engineering school, IMT-Atlantique, recently showcased its “first stand-alone contact lens with a flexible micro battery”. The scaling-down of the battery into a miniscule flexible self-healing Li-ion battery that could power an LED light source for several hours is a major breakthrough. They further use graphene-based flexible electronics. Graphene is a crystalline allotrope of carbon with two-dimensional properties. According to Professor De Bougrenet de la Tocnaye from the optics department at IMT-Atlantique, the wireless scleral contact lens has an eye tracker embedded in it that can be used in an AR helmet. The contact lens does not have a display, but measures the blinking, motions and directions of the eye, which is directly communicated via wif-fi to AR headgear or eyewear.
The Care Harmony Group developed the Beneficial Vision smart contact lenses that are able to deliver monochromatic text and video images. The lenses contain a ring of rechargeable batteries and lasers, which use wave-guide technology to project an image into the central area of the contact lens. The contact lens is combined with wireless ear buds that deliver audio and also track the position of the user’s head and then relay the information to the contact lenses to ensure that the projected image remains a stable overlay on the real world when the head is moved. The company envisions the use of its contact lenses in areas such as education, personal security, law enforcement, medical and aerospace industries, and entertainment. However, although only a prototype has been displayed to the public, pre-orders are currently possible.
The integration of electronics into a small flexible contact lens that must still allow oxygen to reach the eye was a major obstacle to overcome in the creation of smart lenses. However, several breakthroughs have been made. Researchers at Purdue University developed a method called interfacial debonding that involves printing thin-film electronics on to the contact lens material. This provided the much-needed smart functionality, as well as adequate wearability, comfort and unhindered sight.
Several companies are researching intra-ocular smart lenses that would surgically replace the existing lens (that may be impaired due to cataracts). These lenses would have the same smart features as contact lenses, while improving the vision of the user. They would harvest energy according to one of two possible methods. The first is solar power sensors that convert light to electrical power, while the second entails piezoelectric sensors that convert the mechanical eye movement of blinking into electrical power.
And soon we will be able to see in the dark and zoom-in on objects with contact lenses. Scientists at the University of Michigan are developing a contact lens that gives soldiers the ability to see in the dark using thermal imaging. Graphene is used to pick up the full spectrum of light. On the opposite side of the Atlantic, the Swiss Federated Institute of Technology in Lausanne has developed telescopic contact lenses that let the user zoom in on certain objects.
From the innovative developments in smart contact lens technology, it seems that future AR headsets, glasses and smart contact lenses may replace our beloved smart phones in the not-too-distant future. This will free our hands and increase our mobility while effortlessly streaming all the information that we may need at any given place and time. Our eyes and their movements will play a major role in future user interfaces, replacing the well-known typing and touch interactions with smart devices. Well, this will be at least until Elon Musk’s Neuralink perfects the implantation of electronic electrodes in the human brain to directly control devices through our thoughts.
It would be worthwhile to keep a close watch on the exciting and innovative AR technology contact lens developments and you may just see the world transform before your very eyes. Contact lenses have certainly come a long way from the original idea by Leonardo da Vinci in 1508 and the first (uncomfortable) modern lenses created in 1887.