Spectacle Lenses: We have 3 types of lenses

  Single Vision Lenses are prescribed if you need correction for one field of vision, either for distance, intermediate (computer), or items up close (near vision). Eyeglass Lens Direct offers a number of options for the single vision lens wearer. To find out more about our selection of corrective eyeglass lenses for your single vision prescription, search for lenses according to brand name or type. Browse through our categories for Brand Name Lenses, Plastic Lenses, Polycarbonate Lenses, High-Index Lenses, and our category for Photochromic Single Vision Lenses, which include Transitions Lenses, Polarized Lenses, and other options for single vision glasses and sunglasses  
  Bifocal Multifocal eyeglass lenses contain two or more lens powers to help you see objects at all distances after you lose the ability to naturally change the focus of your eyes due to age (presbyopia).
The lens segment (or "seg") devoted to near-vision correction can be one of several shapes:
•    A half-moon — also called a flat-top, straight-top or D segment
•    A round segment
•    A narrow rectangular area, known as a ribbon segment
•    The full bottom half of a bifocal lens  
• A progressive lens gradually and seamlessly changes in power to provide clear distance, as well as intermediate and near vision with no visible segments or demarcation lines.
• Progressive lenses are often referred to as invisible, no-line bifocals. Many people prefer the look of progressive lenses over bifocals, as they look like single vision lenses.
• Progressive lenses offer a smooth transition from distance vision through intermediate vision to near vision, and they supply all the in-between corrections as well. This means that instead of having just two different viewing zones (near and distant), like with bifocals, progressive lenses have progressive powers of correction (from bottom to top), easing eye strain and providing the most natural vision correction.