This Bi-Focal Lens for your Scuba Diving Mask is designed for divers who suffer from Presbyopia aka "Lao Hua", allowing you to easily read their submersible pressure gauge and dive computer while underwater. 

It comes in 1.0 to 2.5 enabling you to find the perfect degree to suit your excact needs. Please bring along your Optical sheet from your optician to facilitate in finding the excact lens that fits your needs.