Optical Lenses

Tuaco Opticians stock a wide variety of optical lenses for prescription glasses.

Our staff will give you expert advice on how to choose the best optical lenses to suit your eyeglass prescription and individual needs.

There are different types of materials you can choose for the lenses of your glasses, the two most popular ones being glass and plastic optical lenses.

Glass and plastic optical lenses both have some advantages and disadvantages:

Advantages and disadvantages of glass optical lenses

Glass lenses have remarkable optics. Some people comment that they can see more clearly or sharply with glass lenses than with plastic ones.

Another important advantages of glass lenses is that they tend to get scratched much less than plastic lenses because the material is harder.

Moreover, if you suffer from a poorer vision, and need to make your lenses thinner, or you need a higher refractive index, glass lenses can be cheaper, in some cases close to half the price of plastic lenses.

In fact, glass lenses can be ordered one stage thinner than plastic, stage 1.9, which does not yet exist for plastic lenses.

However, glass lenses are heavier than plastic lenses, and they have a higher risk of breaking if they are accidentally dropped.

Advantages and disadvantages of plastic optical lenses

One of the principal advantages of plastic lenses (also known as CR39) is that they are much lighter than glass lenses.

They are also more break-resistant, and you can order them in almost all shades and colours of tints, including mirrored-sighted lenses.

However, the material of plastic CR39 lenses is much softer especially if you need to order thin lenses, or lenses with a high refractive index. Plastic lenses require a scratch resistant coating, because they tend to get scratched very easily.

Other types of lenses for prescription glasses

Polycarbonate lenses

Originally developed for safety and strength quality purposes such as airplane windows, polycarbonate eventually started to be used for optical lenses due to its impact-resistant qualities. They are especially recommended for active sportspeople.

These lenses are lighter and thinner than traditional plastic CR39 lenses, they have a UV filter and are scratch-resistant coated.

Photochromatic lenses

Another couple of points to take into consideration when ordering your new optical lenses for prescription glasses is whether you would like your lenses to get dark in the sun.

These types of lenses are called photochromatic lenses. At Tuaco Opticians, we use branded photochromic lenses called Transitions, which adapt to the amount of sunlight in your environment and automatically become darker or lighter in order to give your eyes maximum protection from excessive sunlight and UV ray exposure.

Alternatively, you could also ask our opticians to order sighted sunglasses for you based on your prescription.

Single Vision Lenses

Single vision lenses are prescribed if you require correction for distance only (myopia), for reading only or near-vision only (about 12 to 18 inches, hyperopia) or for intermediate distances (e.g. working at a computer monitor or reading sheet music while playing an instrument like the piano or violin).

Bifocal and Progressive Lenses.

As people grow older, usually over the age of 40, just as wrinkles start appearing on the skin, and white hairs on our heads, their eyes start to find it harder to focus on fine print. This is a condition known as presbyopia and be corrected easily thanks to bifocal or progressive lenses.

Bifocal lenses relieve their users from having to constantly changing their spectacles, for example when they go from watching television to reading their newspaper.

Standard bifocal lenses, provide corrective vision for both distance- and near-vision, with a clear-cut line dividing the distance and reading segment of the lens.

Progressive lenses provide for the same kind of corrections, both distance and reading, however they do not have a clear-cut line displayed on the lens. In this case, the lens power changes vertically across each lens in a gradual and smooth fashion.

Your eye care professional will take careful measurements of your eyes and eyeglass frame in order to customise your progressive lenses so that your eyes can easily access the various powers within the lens for comfortable viewing at all distances.

The major benefit of progressive lenses is that due to their nature they eliminate the annoying problem caused by conventional bifocal and trifocal lenses known as "image jump”, which is experience when your eyes move past the sharply defined boundary between the distance and near parts of the lens.

With progressive lenses, the transition between lens powers within the lens is seamless, letting you change focus from distance- to near-vision and back with no image jump.

High-index lenses

Prescription eyeglass lenses for far-sighted wearers tend to be thin at the centre at thicker around the edges.

With very strong prescriptions, the difference between these two parts is more pronounced such that the lens rim stands out of the frame. This leads to an appearance which many people consider undesirable, more so if the frame is very narrow. These lenses also tend to give the eye a beady appearance.

In these cases, high-index lenses are the ideal choice for people with strong prescriptions who also want to wear thinner, lighter lenses and make their eyeglasses as comfortable and attractive as possible.

High-index lenses work by bending (refracting) light more efficiently, meaning that a thinner high-index lens can achieve the same effect a thicker conventional lens will for people with poorer eyesight.

Since high-index lenses also tend to reflect 50% more light than normal lenses, causing glare and reflections, anti-reflective (AR) lens coating is an important feature you should consider in order to reduce distractions and increase the clarity of your lenses. This is especially important for night drivers and people who work at night.