Smart Autofocusing Eyeglasses

Eye defects occur when the eye cannot focus images from the outside world. This results in blurred vision, which sometimes is so severe that it causes visual impairment. Among the many vision defects, presbyopia is an inevitable, irreversible, universal age-related condition where the crystalline lens in the eye loses its accomodation orthe ability to change the optical power. This defect occurs as a natural result of aging and will ultimately affect any person reaching advanced enough age. It was estimated in 2005 that over 1 billion people worldwide suffered from presbyopia, with approximately 400 million suffering from near vision loss due to the lack of correction technologies.

The most inexpensive and commonly used tools to correct vision errors are fixed power eyeglasses, which haven't seen any improvement since the mid-1800s. Conventional eyeglasses are an ancient piece of technology which originated in Europe's middle ages. A major drawback of such eyeglasses is that they can only correct the lack of accomodation at a particular object distance, since they use fixed power lenses. As a result, conventional eyeglasses can produce sharp images for objects located either far away or near the observer but not both. Bifocal, multifocal and progressive lenses can partially alleviate vision defects, but at the expense of reduced and fragmented field of view. As an example, multifocal lenses have different lens powers in different regions of the lens. With such lenses, it is not possible to see objects clearly over the entire visual field. Further, the effectiveness of conventional eyeglasses is not monitored outside the optometrist's office.

The proposed smart eyeglasses system uses a combination of large-aperture fluidic lenses, ultra-light actuators, object distance sensors and embedded control, communications and computing electronics to continuously produce sharp and focused images at any object range. They can also collect the behaviour and characteristics of the observer's eyes to gauge the effectiveness of the technology and adapt to observer's visual degradation over age.

Inclusion criteria

• Presbyopic
• Less than 1.0 diopter astigmatism
• Eyeglass prescription between -2.5 and +2.5, correctable to 20/20

Exclusion criteria

• Artificial intraocular lens
• Any ocular pathology that would inhibit accommodation of the natural lens