michael.offord@btinternet.com
0191 271 2140

Spectacle Lenses

After your eye examination, you will be assisted with your frame choice, and advised on the most suitable lens option for your prescription and lifestyle requirements.

With a comprehensive spectacle lens portfolio we are able to supply the spectacle lenses which give the very best result when making up your spectacle prescription.

 

Spectacle lenses

Spectacle lenses fall into a number of categories, with the main three types being single vision, bifocal or varifocal.

Single Vision lenses

These are used to correct vision for one specific distance, be that near, long distance or intermediate.  Some single vision lenses can be worn all of the time, but as your Optometrists, we will advise as to whether that is the case with your spectacles.

Bifocal lenses

As the name suggests these lenses are designed to help with vision at 2 different distances.  Bifocal lenses are usually made with the top part of the lens having the long distance prescription and the bottom part having the close work prescription.

Bifocals can be made with the reading portion in a number of different shapes.

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This is a D segment bifocal lens.  It has the benefit that the optical centre of the near vision part of the lens i.e. the part of the reading area which gives the very best vision, is situated at the top of the reading portion.  Also the widest part of the reading area is just below the dividing line, and is the part of the lens the wearer would use.

 

 

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This is a round segment bifocal lens.  It is an older design of lens, but even so is better suited to some prescriptions.

 

 

 

image005This is an executive bifocal lens.  It is used less frequently nowadays, but gives the widest area for close work of any bifocal lens.

 

 

 

Multifocal lenses

These are also called Varifocals or Progressive Power Lenses.  Multifocal lenses combine distance, intermediate and near prescriptions within one lens.  The change from one area to the next is gradual, and so the lens does not have an obvious transition from one power to the next in the way a bifocal lens does.

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Multifocal lenses come in a huge range of qualities and prices; the most up to date lenses give the maximum useful area for each required working distance and the smoothest transition from distance to intermediate to near vision, and so are the most comfortable lenses to use.  With lenses of a lesser quality, some of this comfort is sacrificed.

We are proud of the fact that all of the varifocal lenses in our portfolio are of the most up to date designs, and we are certain that at each given price range the multifocal lenses we supply are the best available.

Lens materials

All spectacle lens types are available in a huge range of materials.  These include standard and thinner lens materials, which are called mid or high index lenses.  This term refers to the refractive index of the spectacle lens, which is a measure of the lens’ ability to bring light to a focus.  A lens made in a high refractive index is therefore thinner and lighter than a comparable lens power made in a standard material.  If follows then that a lens of mid index material would have a thickness and weight between the standard and high index materials.

Some spectacle lens materials have been designed specifically for added strength. This is of particular importance for those patients who wear spectacles in hazardous environments.

Polycarbonate lenses

This is lens material used predominately for those patients who wear spectacles in hazardous environments.  Polycarbonate is the toughest lens material available, being classified as a Grade F industrial lens.  Polycarbonate is softer than most lens materials, which means that it has the ability to absorb impact, however this property also renders the lens surface softer than most other lens materials, so it is more prone to scratching.  If you feel that the added protection which a polycarbonate lens affords would be beneficial to you, we will discuss the advantages and disadvantages with you fully before making the final decision.

Trivex

Trivex is the lens material of choice for rimless spectacle frames.  It is appreciably tougher than the standard plastics material and is also harder than polycarbonate, so is not as easily scratched.  Fitted to a rimless mount, Trivex lenses are usually given a highly polished lens edge which enhances the cosmetic appearance of the finished spectacles.

Trivex has a very slightly higher refractive index than standard plastics, and so is marginally thinner.

Transitions

TransitionsPerfect for everyday use, these lenses are colourless indoors and at night, making them suitable for night time driving. They offer 100% UV protection from the sun’s harmful rays; reducing the risk of Cataracts and Macular Degeneration. Upon exposure to UV light the lenses automatically darken down to give increased visual comfort and reduce eye strain.

Read our guide on Transitions Lenses

Prescription Sunglasses

Polarised

More than just a fashion accessory, sunglasses are a vital part of protecting yourself in the sun as you would with sun cream. Many modern sunglass type frames that can be made up to your prescription.

For those that enjoy water based activities, drive, or simply want the best possible vision, then polarised lenses are the ideal choice.

 

Polarised Lenses

All sunglasses are designed to reduce brightness but not all sunglasses reduce glare. Glare can cause extreme discomfort and reduce visual acuity

What is glare?

Visible light waves from the sun travel in all directions. When sunlight reflects off a horizontal surface, like a road or water, it becomes concentrated horizontally. This is known to result in what we know as glare.

Driving withoutGlare can cause extreme discomfort and reduce visual acuity. Vertical light is useful to the human eye, but glare masks useful light, making it difficult and uncomfortable to see.

Polarised lenses filter out the horizontal light, virtually eliminating glare and increasing visual comfort. In addition, polarized lenses can enhance vision in sunlight, colour contrast and visual comfort, and block 100% of harmful rays. Polarised lenses block glare and allow only vertical light to enter the eye and are especially useful for activities such as driving, skiing and fishing where an appreciable amount of light is being reflected by various surfaces

 

Why are polarised sunglasses beneficial for driving?       

Driving withPolarized sunglasses help when driving by reducing glare caused by reflections of the sun on the cars ahead. Polarizing lenses will provide higher definition vision for driving, remove dazzling effects and reduce eye fatigue.  Tests show that drivers stop quicker when wearing polarised lenses and when faced with a sudden obstacle.

So polarised lenses are perfect in traffic, and snow and near water – all where the intensity of reflected sunshine is the greatest. Likewise for watersports, skiing, fishing and every situation where the reduction of glare is important, polarised lenses are the best possible option.

What are the benefits of polarised lenses for sport?      

For skiing or Snowboarding, polarised lenses enable the wearer to spot bumps or hollows in the snow, as well as increasing visual comfort by reducing glare. For fishing, they enables the wearer to see beneath the surface of the water in comfort, and for virtually every other sport where excellent vision is required in bright conditions, they perform excellently.

At Michael Offord Optometrist we supply polarised lenses as our sun-spectacle lens of choice because they provide the ultimate in protection and visual comfort in bright conditions. They can be supplied with no prescription (plano) or with your single vision, bifocal or varifocal prescription in a variety of lens thicknesses.

 

Why not call in and ask for a demonstration?

Anti-Reflection Coatings

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The materials used and the curved nature of lenses mean that up to 10% of light can be lost through reflections at the lens surfaces, these reflections can be distracting and appear unattractive.

By adding a coating it allows around 99% of light through the lens resulting in increased visual comfort and performance.

Read our guide on Anti-Reflection Coatings