Glasses Frames and Single Vision Lenses

Our vision comes into focus when the retina of our eye focuses on a particular point. This is accomplished by the rate at which light rays are bent when they enter our eye. The medical term for this is ‘index of refraction’. Spectacle lenses work similarly to this, as the density of the lens material bend the rays of light as they pass through the lens itself. Therefore, single vision lenses work well in various materials.

Because single vision lenses are for one viewing purpose only, either distance or for reading, they are available in different index materials to make them lighter and or thinner. Single vision lenses are also available in transition photochromatic plastic, polarised sun lenses and drive wear which could include an anti-reflective coating with a range of tints and treatments depending on where and how you order them.

Fortunately today there is a great choice of lenses on the market that can reduce the weight of your glasses, plus enhance your appearance. Plastic lenses are much lighter than the previous traditional and heavier glass lenses. Because plastic lenses are much softer, they are susceptible to scratches, therefore, it is recommended they are treated with an anti-scratch coating.

‘1.9 Index glass thin lens’ is the thinnest lens material available for very high prescriptions and should really only be used on the highest type of prescriptions, for example +10 or -17 sphere as the weight disadvantage makes it impractical on lower prescriptions where 1.74 thin lens or 1.76 thin lens plastic would be more suitable. These lenses are less prone to chipping or breaking, making them ideal for rimless frames. However, as these lenses reflect more light, it is recommended they are treated with an ant-reflective coating.

The ‘1.76 Index Summit Bi Aspheric Single Vision’ is the latest innovation of ultra thin lenses which are individually crafted to your prescription, and manufactured with Aspheric front and back surfaces to enhance optical performance but also to flatten both the front and rear surface of the lens. This gives a thinner lens substance and when combined with the 1.76 index material gives the thinnest, lightest plastic lens currently available on the market.