Lenses

Spectacle lenses come in many shapes and forms; there are hundreds of types and styles, from many different manufacturers. We at David Kears have access to all lenses currently available in the UK. We are therefore not tied down to any particular product.

There are two main materials used in making spectacle lenses and they are Glass and Plastic.

Lets look at the two types of materials used for spectacle lenses, and see the advantages and disadvantages of both.

Glass

Advantages:

On certain prescriptions a thinner lens is possible.
More scratch resistant than plastic

Disadvantages:

Could be dangerous if broken.
Heavier than plastic.
Not as much choice of lens type as with plastic

Plastic

Advantages:

Lighter than glass.
More choice of lens types.
More impact resistant than glass.
Wider range of tints available.
Can be fitted in more frames styles.

Disadvantages:

Can scratch more easily than glass.

Lens Types

Single vision: A lens with one power/prescription
Bifocal: A lens with two powers/prescription (Distance and Near)
Trifocal: A lens with three powers/prescription (Distance, Near and Intermediate)
Varifocal: - A lens with distance power at the top and changing to reading power at the bottom with an intermediate power between the two. There are no visible segment lines where the powers change from one to the other, as there is with bifocals and trifocals.
Occupational: - A form of varifocal lens that increases the field of view at an intermediate distance e.g. computer screen, with a slightly increased power at the bottom of the lens for reading, writing or computer keyboard.

Within each group of lens type, glass and plastic, different material mixes and lens design give the possibility of flatter, thinner and lighter lenses, which is especially useful with high prescriptions.

Coating and Tints

Spectacle lenses can be tinted and/or coated for cosmetic or prescribed purposes. We provide full and graduated tinting for sunglasses or simply to reduce glare, with the amount of tint being tailored to your requirements.

Light reactive lenses are available in most forms of prescription. We frequently recommend the "Transitions" design. Find out more about Transitions Lenses.

We also provide specific colour tinting to aid those with visual stress disorders associated with Dyslexia, Irlen Syndrome and Migraine.

Lens coatings are becoming evermore sophisticated and are used to greatly increase the durability of a spectacle lens and can be applied to reduce glare and lens fogging. Anti-reflection coatings improve the cosmetic appearance of lenses and enhance visual performance. They have specific benefits for drivers and VDU operators.

Our dispensing opticians would be happy to discuss the appropriate lens options for your needs.