If you require glasses for looking in the distance as you get older, you may require a different pair for reading. In many jobs it is impractical to keep swapping between two pairs of glasses. Bi-focals may be a solution, giving clear distance and near vision in one lens. However, they are not ideal for computer work which is mid-distance. You have to tilt your head back and lean forward to look through the reading lens. You may also have to move your head from side to side to see the entire screen. Vocational progressive lenses are designed to overcome these problems. These will give a wide area of clear vision for distance, viewing the screen and reading and will help improve posture and reduce back ache and headaches.