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Choosing The Perfect Lens

Lens Type

Recommendation Chart
Regular Plastic (CR-39) Lenses
Polycarbonate Lenses
High-Index (1.60 and 1.67) Lenses

Lens Coatings

Scratch Resistant Coating

Anti-Reflective Coating

Transition Lenses

Still need assistance? Contact us and let our opticians help you.

Choosing a Lens Material

The rule of thumb:
If your prescription is lower than 2.75, then regular standard plastic lenses are the best choice for you. If it is above 2.75, a high (refractive) index plastic lens would be better for you. If the glasses are for a child or if you are an active adult and need some extra eye protection or if the lenses will be used with a rimless frame, then polycarbonate lenses will be the best choice for you as they are up to twelve-times stronger than regular standard plastic lenses, making them virtually shatterproof.

The below chart is an excellent guideline for choosing your lens material type:

Recommendation Chart

Lens Material	Sphere range 0 to 3.00	Sphere range 3.00 to 5.00	Sphere range 5.00 to 6.50	Sphere range over 6.00
Regular Plastic	recommended
Polycarbonate	recommended	recommended
High Index 1.60		recommended
High Index 1.67		recommended	recommended	recommended
Photochromatic		lens coating option (learn more)

Regular Standard Plastic (CR-39) Lenses

Our standard plastic CR-39 lenses are a good choice for most people; we usually recommend this lens material type if the sphere (SPH) on your prescription is less than 2.75 for both eyes. If your prescription is below 2.75 there will be little benefit gained from the higher refractive index (thinner) lens types.
CR-39 is the most popular lens material, accounting for over 50% of all eyeglass lenses sold.
It offers excellent optical clarity (comparable to glass lenses).
The lens material has a refractive index of 1.50, equal to that of regular soda-glass lenses.

Polycarbonate Lenses

Polycarbonate lenses' main advantages are that they are up to twelve-times more impact resistant than regular standard plastic lenses making them virtually shatterproof and so they are highly recommended for children, active adults, and anyone with special safety requirements. Polycarbonate lenses are also recommended for rimless glasses, as well as being a good choice if the sphere (SPH) on your prescription ranges between Plano (0 no Rx) to 5.00.
Polycarbonate lenses are up to 40% thinner and 30% lighter than regular standard plastic lenses depending on how high (+) or low (-) your prescription is.
They provide nearly 100% protection from the sun's UV rays.
They are the second most popular lens material in the United States, accounting for approximately 20% of all eyeglass lenses sold.
The lens material has a refractive index of 1.59.

High (Refractive) Index 1.60 & 1.67 Lenses

High refractive index lenses offer the best choice if you want the thinnest most attractive lenses possible.

High Index lenses have higher refraction indexes of 1.60 and 1.67 respectively. The higher the refractive index the more efficiently the lens can bend light. Consequently higher prescriptions can be made with thinner lenses and therefore lighter lenses.

High Index lenses are recommended if the sphere (SPH) on your prescription is greater than 2.75 for either eye. Factors which may affect your choice between the two higher index lenses may include: how much over 2.75 the sphere (SPH) values on your prescription are; how desirable thinner and lighter lenses are; as well as the price of the lenses. The recommendation chart above highlights the most ideal lens material type for each prescription situation.

Thinner lenses have three main advantages: they do not look "thick", they do not magnify or 'minify' your eyes when seen by others, and they are lighter, especially upon your nose.

High-index lenses (as shown at the bottom of the image on the left) can be considerably thinner and lighter, especially with strong prescriptions.

Below is some more information about each of the High Index lenses.

High Index 1.60 Lenses

Are recommended if the sphere (SPH) on your prescription is between 3.00 and 5.00
Are up to 45% thinner than plastic lenses.
Provide nearly 100% protection from the sun's UV rays.
Anti-reflective coating is recommended for best optical performance.
Have a refractive index of 1.60.

High Index 1.67 Lenses

Are recommended if the sphere on your prescription is 3.50 to 7.00.
Are up to 55% thinner than plastic lenses.
Provide 100% protection from the sun's UV rays.
Anti-reflective coating is recommended for best optical performance.
Have a refractive index of 1.67.

Transition (Photochromatic) Lenses

Lenses treated with a transition (photochromatic) coating are virtually as clear as regular lenses, although indoors they will still retain about a 5% tint over uncoated lenses.
They become as dark as most sunglasses outside in bright light, gaining a tint of about 70%, however they generally do not work within a car as the photochromatic tint is activated by UV light that is blocked by most car windscreens, therefore permanently tinted sunglass-style lens coatings are recommended instead if you plan to drive a lot in sunny/bright locations.
They are fast to activate and fast to fade back, offering an appropriate amount of tint according to the current lighting situation.
Transition coated lenses also block 100% of the sun's harmful UV rays, reduce the effects of glare, and improve contrast.
There are currently two main colour options available on the market for transition lenses (brown and grey), and these are both offered by LoveMyFrames.

Choosing a Lens Coating

Scratch Resistant Coating

Whilst treating lenses with a scratch-resistant coating helps prevent scratching, it cannot completely preclude the possibility of your lenses getting scratched. All glasses lenses can get scratched because worldwide they are almost always made from plastics (all our own lenses are plastic), however even lenses made from glass can get scratched. Applying a scratch-resistant coating, covers the lens material with a harder type of plastic that is much more resistant to scratching, but it can still be scratched when exposed to a harder material.

Keeping your glasses in a protective storage case or pouch when not in use will greatly reduce the possibility of scratching and help extend the usable life of your lenses.

Anti-Reflective Coating

Anti-reflective coating is applied to both sides of eyeglass lenses, and on the backside of sunglass lenses. The special properties of the anti-reflective coating allows light to pass more freely through the lens, as well as helping to reduce eye fatigue in many situations, particularly while viewing computer screens and driving at night, as the coating helps reduce glare.

Traditionally uncoated plastic lenses reflect approximate 8%-10% of the light incident on the lens, reducing the amount of light available to your eye, which can be more noticable say whilst night driving; this reflection also creates more glare and while higher index lens materials have numerous benefits, a minor side-effect is that they tend to reflect slightly more of the incident light (between 10%-12%). However, when an anti-reflective coating is applied, high-index lenses and other lens materials will transmit approximately 99.5% of incident light through the lens allowing you to 'see' better at night and experience less glare in all situations.

Anti-reflective coated lenses also make it easier for other people to see the wearer's eyes, and it makes it easier for the wearer to see through the lens, making the lenses seem to 'virtually disappear'. See the images below.

Lenses without anti-reflective coating

Lenses with anti-reflective coating


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