Superhuman Vision: The Future of Contact Lenses. the surrounding world. Not only can it yield knowledge through sight, but it can generate

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1 Kathryn Masci Elisa Warford Writing June 2013 Superhuman Vision: The Future of Contact Lenses Abstract: The eye is an undoubtedly powerful tool that retrieves an abundance of information from the surrounding world. Not only can it yield knowledge through sight, but it can generate important information through non-visual means by studying the biological makeup of its tear fluids. Engineers today are discovering ways to extend the eye s ability by developing contact lenses with advanced technology. With the use of microelectronics and nanotechnology, contact lenses will not only be used to correct the optical function of the eye, but will increase its ability to obtain information by superimposing interactive displays in the wearer s line of vision and by extracting data from the eye s biology to help improve the wearer s health. Introduction: In today s technological world, consumers seek mobile devices with charming visual displays to provide instant access to information. They choose their smartphone based on its ability to play videos, store music, and deliver extraneous applications on a user-friendly interface as well as on its ability to communicate through calling or texting. With the need for video screens that allow for user interaction, screens become larger and larger to display high quality visuals that make it easier to both see and use. However, the greater the device s size, the

2 less mobile it becomes. Consumers must choose between the advanced graphics of bigger screens or the convenience of smaller, more portable phones. New and improved contact lenses might just be the solution to this battle between size and convenience. Envision a contact lens with the function of altering the world around you. Computersimulated visuals pop up as you look at the surrounding world--text appears to inform you of a telephone call, arrows point you in the right direction to help you reach your target destination, and 3D graphics become more engaging since your field of vision increases with a lens directly on your eye. The contact lens will help to create an augmented reality where the generated visuals fluidly interact with the surrounding environment, enhancing the world around you by layering on information. This technology is fast approaching, as researchers look for ways to create virtual reality or, more appropriately named, augmented reality contact lenses for everyday use. Eventually the contact lenses will provide wearers with the most mobile and interactive device yet. Today s Research: Assistant Professor of Electrical Engineering Babak Parviz and his team at the University of Washington are developing contact lenses with the ultimate goal of augmenting reality by creating electronically-produced images in the wearer s line of vision [1]. So far, they have succeeded in embedding a single light-emitting diode (LED) into layers of polyethylene terephthalate (PET) plastic, which form the lens [1][2]. The LED lights up when it receives a signal from a nearby transmitter. An antenna composed of metallic micro-conductors wirelessly

3 surrounds the outer rim of the lens and receives this RF signal in order to obtain power [2]. A general schematic of the lens is shown in Figure 1. Electrical interconnects Biosensor module Sensor readout and control circuit Solar cell module Energy- storage module Semitransparent display and microlens array Telecommunication and power reception antenna Display control circuit Radio and power conversion circuit Figure 1. A schematic of the contact lens developed by researchers at the University of Washington. LED lights are arranged at the lens core to form visual displays [2]. Illustration by Emily Cooper. Although this is a sufficient means of generating electricity in the single LED, Parviz ultimately hopes to light up hundreds more in order to effectively display images and text [2]. With that in mind, alternative means of producing power must be established. The researchers envision miniature solar cells to be the best option [1]. However, creating a contact lens with bionic capabilities poses many challenges. First, all of the technology must fit onto a small, curved surface, about 1.2 millimeters in diameter [2].

4 The materials chosen must also comfortably and safely interact with the eye. In addition, the electronics involved should be transparent and practically undetectable so that the user s view of the environment is not obstructed by the lens inner circuitry. According to Andrew Lingley, one of the core members of Parviz s research team, production of such a lens is made possible by implementing the method of self-assembly to incorporate the complex system [3]. In the process of self-assembly, the various parts of the system spontaneously find the right location and bind to complete the structure [3]. As opposed to laying down each individual component one-byone, the LEDs, antenna, detectors, and other nano-components are positioned at the same time so that they settle in place more naturally. This quasi-systematic procedure makes it easier to manufacture the complex system onto the plastic substrate. While the contact lenses are still in development and are not yet approved for human wear, the engineers have successfully tested their lens on a rabbit for forty minutes without witnessing any damage to its eye [1]. Still, further research is necessary to ensure safe cohesion between the lens and eye. Medical Applications: So far, Professor Parviz and his research team have made slow strides towards producing virtual reality contact lenses. Nonetheless, with their current prototype, they have discovered medical applications that will provide doctors with an abundance of data. Like blood, tear fluid contains a plethora of biomarkers that can ultimately determine a person s level of health [3]. The engineers at the University of Washington discovered that their contact lens can help track glucose levels from the different proteins found in tears through amperometry [4]. In this

5 process, three types of platinum electrodes serve to immobilize glucose oxidase enzymes and convert the enzymes into hydrogen peroxide, which then oxidizes [4]. The resulting oxidation current is recorded to measure the glucose levels of the patient [4]. Their method of amperometric sensing is still faulty, though, due to a recurrent build-up of proteins from the tear fluid on the sensors, skewing the results [5]. However, once the engineers refine the process, the data recovered from the glucose monitoring will help diabetic patients control their blood sugar levels. The researchers at the University of Washington were not the first to realize the potential of contact lenses to collect important biological data. The Switzerland-based company SENSIMED has implemented microelectronics in their Triggerfish contact lenses to monitor introacular pressure (IOP) levels of glaucoma patients over a 24-hour period [6]. The technology in the Triggerfish lenses is comparable to that in Parviz s lenses: an antenna embedded in the lens obtains data points by measuring circumferential changes in the area of the corneoschleral junction, then wirelessly sends the figures to a nearby recording device [6]. At the end of the day, the contact lens will have accumulated about 288 measurements without the user ever noticing its activity [6]. The noninvasive aspect of biological monitoring makes contact lenses an appealing approach for further medical studies. Contact Lenses in the Military: Aside from the commercial and medical prospects of advanced contact lenses, DARPA of the United States Department of Defense is interested in using contact lenses to improve the capability of soldiers during combat. The lens itself will aid the development of DARPA s

6 SCENICC program, which stands for Soldier Centric Imaging via Computation Cameras [7]. Under this program, soldiers become more aware of their surroundings by receiving constant communication and video feeds from ground control units. DARPA is currently working with the engineers at Innovega to develop a contact lens that will make it easier to view incoming feeds shown on head-worn displays (HWD) [7]. The idea behind this lens is unlike that of Parviz s in that the American soldiers will wear them in addition to eyewear. The Innovega ioptiks lenses (as they are called) work by altering the optics of the eye so that it can simultaneously focus on the images displayed on the HWD as well as the surrounding environment. Since the human eye cannot focus on anything closer than about five inches away, without these lenses, viewing video on the HWD would prove impossible. With the contact lenses, the eye can clearly see the close-up displays (within one inch of the eye s surface) with the same definition as the background, as shown in Figure 2. Figure 2. The contact lenses in Innovega s ioptiks allows wearers to clearly view close-up displays at the same definition as more distant views [8]. The lens contains multiple filters to direct the polarized light emitted by the HWD. At the lens center, a small focusing lens aligns the rays of the polarized light, or collimates it, so that the

7 image becomes in-focus [8]. An outer polarization filter surrounding the small focusing lens prevents the polarized light from escaping the core section and interfering with the unpolarized light of the environment [8]. At the same time, an RGB band-pass filter behind the small focusing lens prevents the broad-band environment light from passing through the center region [8]. An illustration of the dual-nature of the lens is shown in Figure 3 below. Polarized Display Light Polarization Filter Ambient Light Polarization Filter Small Focusing Lens Small Focusing Lens RGB Band -Pass Filter RGB Band -Pass Filter Innovega contact lens enables viewing a pixel on the specta Figure 3. Innovega s ioptiks lens filters the polarized light from the head-worn display and the unpolarized light from the surrounding environment to focus the eye onto the screen while simultaneously allowing the eye to view the surrounding area normally [8]. The lens allows the eye to focus on the incoming polarized light without detracting from the surrounding, unpolarized light. The ioptiks system will help soldiers receive information on the front line without interrupting their concentration on their surroundings. Moreover, the contact lenses in conjunction with video eyeglasses will offer the same applications sought after by Parviz and his self-sufficient lenses. As noted by Innovega s chief executive officer Steve Willey, the ioptiks technology makes it so that wearers can experience the tiny video on the glasses as though they are watching a 240-inch television screen from ten feet away [9]. While virtual reality contact

8 lenses are not of the immediate future, ioptiks proves that in the meantime, virtual reality eyewear will come into view until the necessary technology is discovered. Future Prospects: The future of contact lenses is definitely bright. Once engineers successfully develop lenses that can augment reality, daily life will change dramatically for the wearer. These contact lenses will affect how people interact with their environment, for they will have constant access to information no matter where they are. While the intention behind the technology is to enhance the user s life, advancements in contact lenses poses some concerns. For example, will greater access to information cause distractions or make users more productive? Who will have control over what appears in a user s line of vision? Could advertising companies gain access to the wireless technology and post propaganda? If so, what security implications do the lenses pose? These questions cannot be answered until the contact lenses are ready for release, but are important to consider before people begin to look through a new set of eyes. References: [1] A. Lingley. Design and Fabrication of Functional Contact Lenses with Integrated Light Emitting and Photovoltaic Components, Ph.D. dissertation. Dept. Elect. Eng., Univ. of Washington, Seattle, WA, [2] B. A. Parviz. (2009, Sept.) For Your Eye Only. IEEE Spectrum[Online]. 46(9), Available: tp=&arnumber= [3] A. Lingley and B. Parviz. (2008, June). Multipurpose integrated contact lenses. The Neuromorphic Engineer [Online] / Available: article= &category=technologies%3amicroelectromechanical

9 [4] I. Lahdesmaki, A. J. Shum, and B. A. Parviz. (2010, June). Possibilities for Continuous Glucose Monitoring by a Functional Contact Lens. IEEE Instrumentation & Measurement Magazine [Online]. 13(3), Available: ieeexplore.ieee.org.libproxy.usc.edu/xpls/abs_all.jsp?arnumber= &tag=1 [5] (2011, June 4). Look Into My Eyes. The Economist [Online]. S27-S28. Available: %7CA &v=2.1&u=usocal_main&it=r&p=AONE&sw=w [6] K. Mansouri and R. N. Weinreb. (2012, May). Meeting an unmet need in glaucoma: continuous 24-h monitoring of intraocular pressure. Expert Review of Medical Devices [Online]. 9(3), Available: abs/ /erd [7] E. Montalbano. (2012, Feb.). DARPA Works on Virtual Reality Contact Lenses. Informationweek - Online [Online]. Available: search.proquest.com.libproxy.usc.edu/?url= docview/ ?accountid=14749 [8] R. Sprague, A. Zhang, L. Hendricks, T. O Brien, R. Collins, J. Ford, E. Tremblay, and T. Rutherford. (2012). Novel HMD concepts from the DARPA SCENICC program. Proceedings of SPIE [Online] Available: articleid= [9] (2012, Feb. 4). Soon, virtual reality contact lenses to offer 3D panorama. Asian News International (ANI).