Standard Single-Vision Lenses
A Single-vision lens has only one prescription that covers the whole of the lens. These are more common in younger people that may only need glasses for reading, concentrating and driving etc. We will generally prescribe these to you if you have one type of vision. Some people have two pairs of single-vision lenses that have different purposes. They may have a pair for computer work for close-up vision and a pair for driving to aid long-distance vision.
Bifocal Lenses
A Bifocal lens combines two different prescriptions into one lens. The lens is divided horizontally for a top & bottom prescription. This will help someone who may want to have an intermediate vision in the top of the lens for general use, and a near vision prescription in the lower half for reading.
This eliminates the need to have two pairs of single-vision glasses. Bifocal lenses are a more convenient solution as they combine all two visionary needs into one pair of glasses.
Varifocal Lenses
Varifocal lenses are progressive, allowing you to see at any distance. For example, if you are driving, using a computer, shopping or reading, you can wear one pair of glasses that will accommodate your visionary requirements.
Varifocal lenses are generally more necessary for people after the age of 40. This is because as you age you become more long-sighted, caused by loss of elasticity of the lens of the eye. This is known as presbyopia. Both bifocals & varifocal lenses are a great solution if you have more than one vision type.
