There's a wide collection of lenses and coatings available in the world of eyewear. Some designed to improve vision and clarity. Others improve the look of your glasses with stylish tints and eye-catching mirrored lenses. In this blog, we'll walk you through the types of lenses out there and the coatings you need.
Photochromic -
Also known as Transition lenses, these lenses are reactive to sunlight. They will darken in bright sunlight and return to normal clear lenses when indoors or in low light. This prevents the need for constantly switching between pairs of glasses.
Bifocal and Varifocal Lenses -
Bifocals are distance glasses with a visible "D" shaped reading segment on the lens. These allow you to see in the distance through the top of the lens and read through the bottom.
Varifocal lenses blend gradually from your distance vision in the top through your intermediate prescription and into your reading prescription at the bottom. Varifocals allow you to focus at all distances between distance and near (Not all of our glasses are suitable for bifocal lenses. If this is the case the Bifocal option will not be available).
Tints -
Clear -
The standard choice for glasses. They offer clear, scratch resistant lenses.
Sunglasses Grey / Brown -
The most popular choice for sunglasses, especially Ray-Ban and Aviator frames. These lenses are tinted in the selected colour and are also UV protected.
Transitions Grey / Brown -
As mentioned earlier in the blog, these lenses are clear indoors but darken in the presence of UV light. The brighter the sunlight the darker they go. These give you clear lenses indoors and automatically tint out
Transitions also contain UV protection and activate faster and darker when ordered with an Anti-Reflective lens coating.
It is important to note that standard transition lenses do not react very well behind a car windscreen as modern windscreens filter out the UV required to activate the Transitions lenses.
For use behind a car windscreen, choose Transitions XTRActive lenses which react moderately behind a car windscreen.
Polarised Grey / Brown -
Polarised lenses are sunglass lenses similar to the Grey / Brown tint options above. However, polarised lenses have a filter inside the lens which filters out any light that has been reflected from a flat surface such as a wet road, car bonnet or water.
Mirrored Lenses -
Mirrored sunglass lenses can help to reduce the effects of glare but their benefits are mainly aesthetic. Bold colours such as red and gold are perfect for those looking for eyewear that is a little more eye-catching. We offer Grey with Silver Mirror, Brown with Gold Mirror, Grey with Blue Mirror and Grey with Fire Red Mirror.
Thickness -
Firstly each lens has what we call a "Refractive Index" The way in which the refractive index is calculated is not important at this time. What is important is what it means to the thickness of the lens.
Most people think that when we say a 1.6 lens that this means it is going to be 1.6mm thick but this isn't true. A higher number means a thinner lens. This is because materials that bend light more than others have a higher “Refractive index” and hence a shorter or longer focal length. This means that the same correction and focal length can be achieved from “less” lens (material) making them thinner.
Standard Plastic 1.5 -
Ideal for most prescriptions (prescriptions with powers stronger than +3.00 and -3.00 will start to look thick, powers between the two will look fine).
Plastic 1.6 Thin -
An ideal option for prescriptions up to +4.00 and down to -4.00. 1.6 lenses are approx 23% thinner than standard plastic. Prescription outside this range will start to look thick.
Plastic 1.67 Very Thin -
Probably the most popular of the thinner lens options. Approx 15% thinner than the 1.6 and 25% flatter. Ideal for prescriptions up to +6.00 and down to -6.00 prescription outside this range will look thick.
Plastic 1.74 Thinnest -
The thinnest plastic lens available on the market. Approx 50% thinner than the 1.5 standard plastic and 30% lighter than the glass equivalent. Great for mid to high prescriptions.
Blue Light Control
LCD and LED screens such as phones, tablets and TV screens all emit blue light. This blue light is a natural phenomenon and is present in daylight to help us stay awake. Over-exposure however, can cause eye strain, eye fatigue and sleeplessness. Blue Light Control helps to neutralise the adverse effects of blue light and prevent eye strain and fatigue. It keeps your eyes in better condition and maintains clarity.
The wide range of lenses and coatings can make it tricky to know what's right for you. If you're unsure, speak to your optician and they will be able to recommend some combinations that are right for you. If you're still unsure, contact us and we can walk you through the options that we offer so you can get the most out of your glasses. Alternatively, take a look at our help section for more information.
Need to pick up some new frames before deciding on your lenses and coatings? Take a look at our wide range of glasses and sunglasses available at Spex4less.