Abstract: An embodiment of an eye-mountable device includes an optical lens; an accommodation actuator to provide vision accommodation for the optical lens; a controller including an accommodation logic to select one of a plurality of vision accommodation states for the device, the plurality of vision accommodation states including at least a failsafe focal distance; and a failsafe subsystem including a system health detector, the system health detector to monitor for one or more operational indicators for the device, wherein the failsafe subsystem is to cause the device to transition to a failsafe mode upon the failsafe subsystem identifying a failure condition for the device, the failsafe mode includes setting the vision accommodation state to be the failsafe focal distance.

Abstract: Techniques and mechanisms for sensing an overlap of an ophthalmic device by an eyelid of a user while the ophthalmic device is disposed in or on an eye of the user. In an embodiment, a circuit, disposed in a sealed enclosure of the ophthalmic device, interacts via an electromagnetic field with a film of tear fluid that is formed on the ophthalmic device. Based on the electromagnetic interaction, an oscillation characteristic of the circuit is evaluated. The oscillation characteristic varies with a resistance that is due in part to an eyelid of the user overlapping at least some portion of the ophthalmic device. Based on the evaluated oscillation characteristic, an amount of the eyelid overlap is determined by circuitry of the ophthalmic device. In another embodiment, the amount of eyelid overlap is used to determine one or more characteristics of gazing by the user's eye.

Abstract: This disclosure relates to systems and/or methods for detection of eye blinking using an active contact lens with multiple sensors and detecting orientation of the active contact lens.

Abstract: Apparatus, systems and methods employing contact lens sensors are provided. In some aspects, a contact lens includes a substrate that forms at least a portion of the body of the contact lens; an optical communication device disposed on or within the substrate; and a photodetector disposed on or within the substrate, wherein the photodetector harvests light emitted from a device and generates power from the harvested light. In some aspects, an apparatus comprises a tag having a circuit including: an optical communication device; and a photodetector that harvests light received and generates power from the harvested light. The tag can be disposed on or within a contact lens in various aspects.

Abstract: This disclosure relates to systems and/or methods for subtracting in the current domain an output current primary signal from a primary sensor from an output current reference signal from a reference sensor to produce a frequency output signal indicative of the difference between the output current primary signal and the output current reference signal.

Abstract: Disclosed herein are methods and systems for adjusting the power level of an external reader of an electronic device. The external reader transmits power to the electronic device with a radio frequency electromagnetic signal. The electronic device may rectify the radio frequency electromagnetic signal and create a rectified voltage. The rectified voltage may be positively correlated to the power level transmitted by the external device. The rectified power can be used to power a component of the electronic device, such as a component configured to measure either a voltage or power associated with the rectified voltage. The electronic device may communicate the measured voltage or power back to the external reader. Based on the communicated voltage or power, the external reader may adjust its power level of the transmitted power.

Abstract: Deterministic asymmetry in a random number generator can be mitigated by a circuit that includes a first inverter, a second inverter, a first capacitor, a second capacitor, a first switch, and a second switch. The first inverter can include a first input terminal and a first output terminal. The first inverter can have a first inverter threshold voltage. The second inverter can include a second input terminal and a second output terminal. The second inverter can have a second inverter threshold voltage. The first capacitor can be conductively coupled between the first output terminal and the second output terminal. The second capacitor can be conductively coupled between the second output terminal and the first input terminal. The first switch can be conductively coupled between the first input terminal and the first output terminal. The second switch can be conductively coupled between the second input terminal and the second output terminal.

Abstract: Techniques and mechanisms for sensing an overlap of an ophthalmic device by an eyelid of a user while the ophthalmic device is disposed in or on an eye of the user. In an embodiment, a circuit, disposed in a sealed enclosure of the ophthalmic device, interacts via an electromagnetic field with a film of tear fluid that is formed on the ophthalmic device. Based on the electromagnetic interaction, an oscillation characteristic of the circuit is evaluated. The oscillation characteristic varies with a resistance that is due in part to an eyelid of the user overlapping at least some portion of the ophthalmic device. Based on the evaluated oscillation characteristic, an amount of the eyelid overlap is determined by circuitry of the ophthalmic device. In another embodiment, the amount of eyelid overlap is used to determine one or more characteristics of gazing by the user's eye.

Abstract: Techniques and mechanisms for determining an amount of accommodation for an ophthalmic system are described. In an embodiment, the ophthalmic system includes a first circuit and a second circuit, each comprising a respective photodiode. The second circuit is configured to provide a light response profile that is more linear than a light response profile provided by the first circuit. Light sensing by the first circuit results in generation of a first signal indicating a level of ambient light in a surrounding environment. Other light sensing by the second circuit results in a second signal being generated. An amount of accommodation is determined based at least in part on the second signal.

Abstract: An embodiment of an eye-mountable device includes an optical lens; an accommodation actuator to provide vision accommodation for the optical lens; a controller including an accommodation logic to select one of a plurality of vision accommodation states for the device, the plurality of vision accommodation states including at least a failsafe focal distance; and a failsafe subsystem including a system health detector, the system health detector to monitor for one or more operational indicators for the device, wherein the failsafe subsystem is to cause the device to transition to a failsafe mode upon the failsafe subsystem identifying a failure condition for the device, the failsafe mode includes setting the vision accommodation state to be the failsafe focal distance.

Abstract: An eye-mountable device including a lens including a polymeric material, the lens operable to be removably mounted over a corneal surface of an eye and to be compatible with a motion of an eyelid when the concave surface is so mounted; a sensor coupled to the lens and operable to provide output data indicative of whether an eyelid of an eye on which the lens is mounted is closed; and a display operable to display a light signal in response to the output data from the sensor that the eyelid is closed. A method including determining whether an eyelid of a wearer of an eye-mountable device is closed; and when an eyelid of a wearer is closed, sending a light signal from the eye-mountable device.

Abstract: Techniques and mechanisms for sensing an overlap of an ophthalmic device by an eyelid of a user while the ophthalmic device is disposed in or on an eye of the user. In an embodiment, a circuit, disposed in a sealed enclosure of the ophthalmic device, interacts via an electromagnetic field with a film of tear fluid that is formed on the ophthalmic device. Based on the electromagnetic interaction, an oscillation characteristic of the circuit is evaluated. The oscillation characteristic varies with a resistance that is due in part to an eyelid of the user overlapping at least some portion of the ophthalmic device. Based on the evaluated oscillation characteristic, an amount of the eyelid overlap is determined by circuitry of the ophthalmic device. In another embodiment, the amount of eyelid overlap is used to determine one or more characteristics of gazing by the user's eye.

Abstract: Systems for determining an individual's current focal distance by measuring parameters associated with binocular vision focusing using one or two contact lenses are provided. In an aspect, a system includes a first contact lens and a second contact lens respectively configured to be worn over first and second eyes of an individual. The first contact lens and the second contact lens respectively include first and second circuits configured to respectively generate first data related to the first eye and second data related to the second eye for determining the current focal distance.

Abstract: An embodiment of an eye-mountable device includes an optical lens; an accommodation actuator to provide vision accommodation for the optical lens; a controller including an accommodation logic to select one of a plurality of vision accommodation states for the device, the plurality of vision accommodation states including at least a failsafe focal distance; and a failsafe subsystem including a system health detector, the system health detector to monitor for one or more operational indicators for the device, wherein the failsafe subsystem is to cause the device to transition to a failsafe mode upon the failsafe subsystem identifying a failure condition for the device, the failsafe mode includes setting the vision accommodation state to be the failsafe focal distance.

Abstract: The present disclosure provides methods and apparatuses for providing an audible feedback based on a proximity or a link quality between an external reader and a tag. The external reader transmits power to the tag with a radio frequency electromagnetic signal. The tag may rectify the radio frequency electromagnetic signal and create a rectified voltage. This rectified voltage may be used to power various components of the tag. Once it receives power from the reader, the tag may communicate information back to the external reader. The information communicated back to the reader is communicated by modulating an antenna impedance of the tag. By modulating the impedance, the tag will backscatter radiation transmitted by the reader. The reader is able to create an audio output based on determining the proximity or link quality from the reader to the tag based on the backscatter radiation it receives from the tag.

Abstract: Apparatus, systems and methods employing contact lens sensors are provided. In some aspects, a contact lens includes a substrate that forms at least a portion of the body of the contact lens; an optical communication device disposed on or within the substrate; and a photodetector disposed on or within the substrate, wherein the photodetector harvests light emitted from a device and generates power from the harvested light. In some aspects, an apparatus comprises a tag having a circuit including: an optical communication device; and a photodetector that harvests light received and generates power from the harvested light. The tag can be disposed on or within a contact lens in various aspects.

Abstract: Apparatus, systems and methods of contact lenses with power sources are provided. In some aspects, a contact lens can include a substrate; and a circuit. The circuit can include: one or more sensors disposed on or within the substrate; circuitry disposed on at least a portion of the substrate; one or more photovoltaic cells disposed on at least a portion of the substrate; and a hybrid power component that supplies at least one of two or more different types of power to the circuitry, wherein at least one of the two or more different types of power is radio frequency/inductive power. In various aspects, other types of power can be solar and/or microelectromechanical system power. Additionally, in various aspects, photovoltaic cells can be arrayed in different configurations and/or over a significant portion of a viewing surface of the contact lens. In some aspects, the photovoltaic cells can be transparent.

Abstract: Disclosed herein are methods and systems for adjusting the power level of an external reader of an electronic device. The external reader transmits power to the electronic device with a radio frequency electromagnetic signal. The electronic device may rectify the radio frequency electromagnetic signal and create a rectified voltage. The rectified voltage may be positively correlated to the power level transmitted by the external device. The rectified power can be used to power a component of the electronic device, such as a component configured to measure either a voltage or power associated with the rectified voltage. The electronic device may communicate the measured voltage or power back to the external reader. Based on the communicated voltage or power, the external reader may adjust its power level of the transmitted power.

Abstract: This disclosure relates to systems and/or methods for detection of eye blinking using an active contact lens with multiple sensors and detecting orientation of the active contact lens.

Abstract: The present disclosure provides methods and apparatuses for providing an audible feedback based on a proximity or a link quality between an external reader and a tag. The external reader transmits power to the tag with a radio frequency electromagnetic signal. The tag may rectify the radio frequency electromagnetic signal and create a rectified voltage. This rectified voltage may be used to power various components of the tag. Once it receives power from the reader, the tag may communicate information back to the external reader. The information communicated back to the reader is communicated by modulating an antenna impedance of the tag. By modulating the impedance, the tag will backscatter radiation transmitted by the reader. The reader is able to create an audio output based on determining the proximity or link quality from the reader to the tag based on the backscatter radiation it receives from the tag.