Switchable liquid crystal contact lenses: Dynamic vision for the ageing eye

TY - GEN

T1 - Switchable liquid crystal contact lenses

T2 - 2014 SPIE Photonics West on Emerging Liquid Crystal Technologies IX Conference

AU - Milton, Harry E.

AU - Gleeson, Helen F.

AU - Morgan, Philip B.

AU - Goodby, John W.

AU - Cowling, Stephen

AU - Clamp, John H.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - The inability of the eye to focus on nearby objects, presbyopia, is suffered by ~100% of people over the age of 50. Liquid crystal (LC) spectacle lenses have shown great potential for correcting presbyopia. However, correcting presbyopia in contact lens users has proven elusive and existing commercial options suffer significant compromises in vision and comfort. We describe a novel contact lens that includes a liquid crystal element that offers to correct presbyopia without the compromises associated with other technologies. We fabricated variable focus lenses using a balanced optical system, providing the additional optical power presbyopes require for near vision (typically +1.00 D to +2.00 D). The system uses positive optical power from the two substrates and variable negative optical power from the LC layer to form a balanced optical system which, when unpowered, corrects distance vision. Upon voltage application, the liquid crystal layer decreases in refractive index, resulting in additional optical power in the system, offering correction equivalent to reading glasses. Our new technology is based on a traditional contact lens material which could be placed directly on the eye. The liquid crystal lens employed is well suited to the small optical areas associated with contact lenses. We compare several different LC materials and geometries which are suitable for our application, and discuss the influence of material and geometry on switching times, optical quality and operating voltage. Our contact lenses typically switch ±2.00D in response to < 10 Vrms with response times of the order of a second.

AB - The inability of the eye to focus on nearby objects, presbyopia, is suffered by ~100% of people over the age of 50. Liquid crystal (LC) spectacle lenses have shown great potential for correcting presbyopia. However, correcting presbyopia in contact lens users has proven elusive and existing commercial options suffer significant compromises in vision and comfort. We describe a novel contact lens that includes a liquid crystal element that offers to correct presbyopia without the compromises associated with other technologies. We fabricated variable focus lenses using a balanced optical system, providing the additional optical power presbyopes require for near vision (typically +1.00 D to +2.00 D). The system uses positive optical power from the two substrates and variable negative optical power from the LC layer to form a balanced optical system which, when unpowered, corrects distance vision. Upon voltage application, the liquid crystal layer decreases in refractive index, resulting in additional optical power in the system, offering correction equivalent to reading glasses. Our new technology is based on a traditional contact lens material which could be placed directly on the eye. The liquid crystal lens employed is well suited to the small optical areas associated with contact lenses. We compare several different LC materials and geometries which are suitable for our application, and discuss the influence of material and geometry on switching times, optical quality and operating voltage. Our contact lenses typically switch ±2.00D in response to < 10 Vrms with response times of the order of a second.

KW - Contact lens

KW - liquid crystal

KW - presbyopia

KW - switchable lens

UR - http://www.scopus.com/inward/record.url?scp=84897508594&partnerID=8YFLogxK

U2 - 10.1117/12.2044676

DO - 10.1117/12.2044676

M3 - Conference contribution

AN - SCOPUS:84897508594

SN - 9780819499172

VL - 9004

BT - Proceedings of SPIE

PB - SPIE

Y2 - 5 February 2014 through 5 February 2014

ER -