Polynomial-Curved Bespoke Prescription Lens for Respiratory Protection

Most single-lens full facepiece air-purifying respirators (APR) are unable to provide vision correction via the primary lens of the respirator due to its complex geometry and the requirement of providing different prescription strengths for each of the wearerÆs eyes. The Dept. of Defense (DoD) seeks a prescription lens solution that can provide visual correction on a polynomial curved surface (e.g. M50 respirator lens) with varied prescription strength as needed at either eye. These lenses would need to be made-to-order with specified diopter strengths ranging from -10.00 to +8.00 available on either half of the respirator lens to accommodate conditions such as anisometropia. The lens would also need to maintain the current shape and size of the primary lens of an M50. Since the primary lens of a full facepiece respirator is a part of the critical sealing surface, this lens will also need to have threat agent permeation resistance characteristics required by the NIOSH Statement of Standard for Chemical, Biological, Radiological, and Nuclear (CBRN) Full Facepiece APR. Bodkin Design & Engineering (BD&E) and our development partner Zenwa will demonstrate a solution which can be applied to any clear surface, flat or curved, to correct a wearerÆs vision. This solution entails on-demand printing of Fresnel lenses of moderate power over large area. This technology uses direct laser writing on photopolymer to fabricate the lenses. The corrective lens can be fabricated on a flexible substrate and then adhered right on the curved internal surface of the M50 lens, thereby protecting it from any environmental hazards.