Reading Glasses with Transition Photochromic, aspheric hard resin bifocal lens Outdoor Readers Aviator Sunglasses for UV400 /Anti Glare/ in Reading Magnification 1.00 to 3.00 strength,Black,+3.0 : Amazon.co.uk: Health & Personal Care
The royal class: photochromic glasses (TRANSITIONS® XTRActive®)
Transition Lenses: About Photochromic Glasses | Yesglasses