Magento Module (Extension) eye prescription is for adding lenses (eyeglasses and sunglasses) prescription (Sphere, Cylinder, Axis, Near/Add, PD) to a product of site powered by magento. The customer can enter this prescription in a special form on the product view page. The prescription is saved as a Magento custom product option and is visible on the order email, customer order details and on Magento admin order details. The prescription is also saved in the customer account, the customer can view/modify his prescription.
Module will be exactly like this example : https://www.eyebuydirect.com/