We are experts in High Prescriptions

Trust your prescription glasses to Specfactory.co.za. World-class ophthalmologists and opticians run the factory and ensure the quality and high standards of each and every prescription eyeglass and lens. No matter whether you have -28.00 sphere, or +6.75 cylinder or prism corrections, Specfactory.co.za will supply top quality lenses to fit your prescription.

Want to get an idea of which lenses might be best for you?

Take our quick tour here and find out!

“Tell me and I’ll forget. Show me and I’ll remember. Involve me and I’ll understand.”
— Confucius

With any type of purchase, most people who are "looking for the best price" are really looking for the best overall value, that’s why here at Specfactory.co.za the highest quality lenses are used in fabricating your prescription eyeglasses.  Top manufacturers in their field, from every corner of the world, using the most advanced polymers and techniques, produce these lenses.

Here at Specfactory.co.za we explain in depth, the differences between different types of lenses and which lenses would best suit you. We keep you informed of the latest designs and technology so you can make the right purchase.

We have

Dynamic Designs

Magnificent Materials

Fantastic Finishes

Superb service

Lens Info and Options

Lens Materials

Glass

Crown Glass is still the “gold standard” in lens performance. Glass lenses provide the best optics and clarity of vision. However, many eye care professionals shy away from using glass because it can be broken. Glass lenses are available in an almost limitless variety of designs, from single-vision, multifocal’s, progressive lenses and occupational designs. These lenses must be tempered for impact resistance.

Pros

        •        Provide the best optics and clarity of vision

Cons

•        Very heavy - much heavier than plastic

•         Breakable thus can cause injury

CR-39

Is often referred to as CR-39, hard resin or standard plastic. Developed by PPG, 60 years ago this is arguably the most commonly used lens material today. Available in a wide variety of lens designs, from single vision to progressive lenses to occupational multifocal’s, it is easily tinted and usually ultra-violet protective and impact-resistant. A much lighter lens material (approximately 50% lighter) than glass, however, is far less scratch resistant than glass and often must be coated to improve its scratch resistant characteristics
Index: 1.5

Pros

•      Lighter than glass

•         Readily tintable

•         Less likely to fog

         Good optical clarity

Cons

•         Susceptible to scratching (correctable by coating)

•         Lower index of refraction makes it less suitable for higher-powered prescriptions

Polycarbonate

While its optical characteristics are less than ideal, polycarbonate, is gaining in popularity and acceptance. It is the same material used for bulletproof glass because it’s extremely impact-resistant, in fact the most impact resistant of all lens materials. Consequently, polycarbonate is the material often used for safety and children’s eyewear. With an index of 1.59, polycarbonate also produces thinner, lighter lenses than glass or plastic (with the exception of Trivex). These factors along with polycarbonate’s inherent UV protection and pricing make it a popular material.

Index: 1.59

Pros
Thinner and lighter than glass and plastic
Highly impact resistant (used for safety glasses)
Inherent UV protection

Cons
Poor optical quality
Susceptible to scratching (correctable by coating)
Susceptible to stress fractures in drill mounts
Does not readily accept tint
Only available at the moment in Single Vision

Safewear  

Often called  - Performance without Compromise

Single vision Safety lenses in Trivex® resin.
Trivex® is a new plastic lens monomer developed by PPG Industries. It is a strong, light and thin material with a very high impact resistance equivalent to polycarbonate.
Trivex® is distributed by Hoya as PNX and by Younger Optics as Trilogy® and by us as Safewear

These lenses are the first lenses to deliver a great combination of quality optics, lightweight/thinness, and high impact resistance. Extremely thin and light, in fact it is the lightest material on the market and has a mid index of 1.53.

Safewear Lenses are excellent for the following:

Sunglasses: Safewear lenses very hard but can be tinted easily so they makes excellent Sunglasses.

Children glasses: Safewear lenses have the perfect combination of impact resistance, excellent optics, and lightweight qualities that are important for children’s eyewear.

Rimless Glasses: They are excellent! - With Rimless lenses you need to balance the best properties of excellent optics, lightweight and tough impact resistance. Trivex® unique properties make a beautiful edge polish and being thin and light they really make a superb looking pair of trendy rimless glasses

Properties of Trivex® compared to other lens materials

Safewear is obviously stronger than polycarbonate. However both materials far exceed the impact performance of other lens materials. It has 100% UV protection from both UVA and UVB rays and Trivex® is unaffected by most common chemicals and solvents.

Our range of lenses available in Trivex® is expanding all the time, please contact our customer services department to discover the latest releases.

Pros

• Thinner and lighter than glass and any other plastic lens on the market.
• Readily tintable
• Less likely to fog
• Highly impact resistant (used for safety glasses, sports glasses, motor Racing & Flying)
• Inherent UV protection
• Good optical clarity - Better optical quality than polycarbonate
  
  Cons
  Only available at the moment in Single Vision
  Susceptible to scratching (correctable by coating)
  
  Mid - Index
  
  Mid-Index Hard Resin has a large following and usually means 1.523 to 1.56 index lenses. They are lighter and thinner than 1.49, and they offer a thin lens profile, available in a variety of lens designs, including single-vision, bifocal and progressive lenses. Most lens manufacturers recommend an anti-reflective coating for these lenses to reduce internal and external reflections.

Hi-Index

Hi-Index Hard Resin has become a catchall phrase encompassing 1.60, 1.66/1.67 and 1.71 index lenses. While not necessarily lighter in weight, they offer the thinnest lens profiles and are available in a variety of lens designs, including single-vision, bifocal and progressive lenses. Most lens manufacturers recommend an anti-reflective coating for these lenses to reduce internal and external reflections.

High index lenses polymers typically refer to products with an index higher than 1.58. High index lenses require flatter curves than their lower index counterparts, resulting in thinner and lighter lenses. Furthermore, aspheric curves come standard in many high index products, particularly 1.66 and 1.70 products, and are available in 1.61.

Aspheric Lenses

Asphericity reduces spatial distortion, reduces magnification or minimisation, and further helps maintain a thin and flat lens profile. High index material, however, tends to have a lower Abbe value which could potentially affect patients who are sensitive to chromatic aberration. Also higher index and flatter curves tend to result in more backside and inner-surface reflections. AR coatings are usually recommended for high index lenses to eliminate these reflections.

Index: 1.61, 1.67, and 1.74

Pros of Hi Index lenses

Thinner and lighter than glass and plastic
Better optical quality than polycarbonate

Cons
Susceptible to scratching (correctable by coating)
Susceptible to backside and inner-surface reflections (correctable with AR)

The picture below explains how the lens gets thinner when higher index material is used to make the lens - look how thin the 1.67 is!

Index 1.5 to High index 1.67

Lens Types

Single Vision Lenses

Reading
Distance
Intermediate

Are all Single Vision Lenses, and as the name suggests, correct a single error and only a single lens is needed to correct you sight. When a myopic or hyperopic condition exsists in the eye, glasses are required to correct vision in Reading, intermediate, and distance. Minus powered single vision lenses are used to correct myopia and plus powered single vision lenses are used to correct hyperopia. For example, Single vision lenses are used as reading glasses for Presbyopia patients who have clear distant vision, but require correction for close objects.

Progressives Lenses

Note: we do not sell these at the moment, we will shortly.
Unlike bifocals and blended multifocal’s, progressive lenses offer a continuous, gradual change in power from the upper distance portion of the lens to the lower near portion. Consequently, in addition to providing correction for all distances, progressive lenses have no visible lines and thus are more aesthetic than bifocals or trifocals. Progressives are available in many different designs to accommodate a patient’s viewing requirements, as well as various fit heights to match different frame sizes. Custom progressive lenses are now even available, which can be ground specifically for an individual, taking precisely into consideration the individual’s anatomy, visual requirements, and frame choice.

Blended Multifocal Lenses

Note: we do not sell these.
Blended multifocal’s are bifocals with no visible line between segments, but unlike progressive lenses have no gradual change or useable region between existing refractive correction and the add power. The line between segments is simply blended, as the name suggests, making it less visible.