Boston XO contact lenses are rigid gas permeable contacts created with an extra tough, stable Dk material for daily use. Boston XO lenses are spherical and aspherical lenses designed for patients with myopia, hyperopia and presbyopia who may need extra considerations conventional contact lenses cannot provide. Boston XO contacts are custom made to ensure the best fit and use for every patient based on the parameters supplied by your eye doctor. There is one Boston XO contact lens per each vial.All RGP lenses are a final sale. No refunds or exchanges.