Alvita Casey's 1 dioptre glasses are a type of glasses designed to correct the vision of people who have a slight difficulty in focusing on close objects, known as hyperopia. Diopter refers to the measurement of correction needed to achieve sharp vision. In this case, Casey 1 dioptre glasses are designed to correct farsightedness at a low level, i.e. one dioptre. These glasses are made of high quality materials and polycarbonate lenses, making them strong and durable. They come with a lightweight, comfortable frame that fits snugly on the face for comfort and clear, sharp vision.