Glasses with Adjustable Focal Length

Glasses with adjustable focal length (adjustable optical power) are necessary for patients with a weak eyes accommodation.

Currently, the industry produces multifocal glasses with different surface curvature on different parts of the lenses. The main drawback here is the high price. Another proposal exists to create glasses containing a layer of liquid crystal controlled by electricity. The main drawback of it is the small range of optical power alteration. There is also known design of glasses, each lens of which consists two layers of plastic with a bag of liquid between them. The ophthalmologist adjusts optical power when issuing points to the client. Their disadvantage consists from the inability to adjust the optical power during operation.

The author presents the project of glasses with the focal length that may be adjusted by the patient. Each lens contains 2 plastic layers. Liquid with a high refractive index fills the gap between the layers. These lenses are connected with liquid quantity regulators by thin tubes. The regulator is made in the form a soft bag on the end of the tube, compressed by the flaps with a screw. The patient can adjust the optical power of each lens by manipulating by the fingers at the end of the glasses arcs. Glasses contains just 15 simple and cheap parts in the simplest case. Calculation range is ± 2 diopters. There are also other variants of the device.

Summary: Patient-controlled household glasses are described, The expected cost will not be high, design is not sophisticated.