When choosing the enhancements for your lenses, you are faced with a variety of options. Selecting lens enhancements is an important decision, from both a functional standpoint, as well as for your comfort and enjoyment. Your lens enhancement selection affects your vision clarity at work, home, and through your hobbies.
do what no other lens or lens treatment can – block blinding glare.
In addition, polarised lenses can enhance visual acuity, colour contrast and visual comfort, and block 100% of harmful UVA and UVB light. We’ve all experienced glare in our daily lives, perhaps spending the day at the beach, driving in a car with the sun reflecting off the dashboard, roadway or bonnet. Usually, this glare is annoying and uncomfortable on the eyes, but when the angle of reflection is just right, the glare can become blinding and often downright dangerous, as in the case of driving a vehicle.
Ordinary tinted sunglass lenses only cut down on ambient light that reaches the eye, or, light transmittance. By their very nature, they cannot block glare. Only polarised lenses can block out this dangerous, blinding glare.
eyeglass lenses are the right choice if you want thinner, lighter lenses and eyeglasses that are as attractive and comfortable as possible.
Thinner, lighter high-index lenses are especially recommended if you have a strong eyeglass prescription for nearsightedness, farsightedness or astigmatism.
Most eyeglass wearers are nearsighted, which requires corrective lenses that are thin in the center but thicker at the edge of the lens. The stronger the prescription, the thicker the edges.
Most of today’s fashionable frames are made of plastic or metal with rims thinner than the lens itself. Also, popular rimless mountings mean that the edges of the lenses are completely exposed. In either case, the lens edges are highly visible, and thicker edges can detract from the appearance of your eyewear.
Photochromic Lenses/ Transition Lenses
often called transitions or, darken to a sunglasses tint when exposed to sunlight, or U/V ultraviolet, and return to a clear state when indoors, away from U/V light.
They are typically used as sunglasses that conveniently switch from a clear lens indoors, to a sunglasses depth tint when outdoors, and vice versa and typically take around 30 seconds to fully darken and approx 2 – 5 minutes to return to a clear state.
Tiny molecules of silver halide and chloride are embedded within a photochromic lens which is invisible and clear until exposed to sunlight/UV rays. A chemical process takes place when they are exposed to sunlight/UV and this causes the molecules to move, change shape and absorb the light. This process changes the molecules and they darken to a sunglasses shade/tint.
The photochromic lens will remain in this ‘darkened’ sunglasses state whilst exposed to sunlight/UV and the molecules will reverse the process once the lenses are removed from the sunlight/UV rays returning to the original ‘transparent/clear’ lens.
Anti-reflective coating (also called “AR coating” or “anti-glare coating”) improves vision, reduces eye strain and makes your eyeglasses look more attractive.
These benefits are due to the ability of AR coating to virtually eliminate reflections from the front and back surfaces of your eyeglass lenses. With reflections gone, more light passes through your lenses to optimize visual acuity with fewer distractions (especially at night), and the lenses look nearly invisible — which enhances your appearance by drawing more attention to your eyes and helping you make better “eye contact” with others.
AR coating is especially beneficial when used on high-index lenses, which reflect more light than regular plastic lenses. Generally, the higher the index of refraction of the lens material, the more light that will be reflected from the surface of the lenses.
For example, regular plastic lenses reflect roughly 8 percent of light hitting the lenses, so only 92 percent of available light enters the eye for vision. High index plastic lenses can reflect up to 50 percent more light than regular plastic lenses (approximately 12 percent of available light), so even less light is available to the eye for vision. This can be particularly troublesome in low-light conditions, such as when driving at night.
Today’s modern anti-reflective coatings can virtually eliminate the reflection of light from eyeglass lenses, allowing 99.5 percent of available light to pass through the lenses and enter the eye for good vision.
By eliminating reflections, AR coating also makes your eyeglass lenses look nearly invisible so people can see your eyes and facial expressions more clearly. Anti-reflective glasses also are more attractive, so you can look your best in all lighting conditions.
While many people choose sunglass lens colors purely for aesthetic reasons, did you know that different lens colors actually serve different purposes? The tint of your sunglass lenses can enhance your depth perception and reduce eye fatigue in different environments, improving your performance across a number of sports and activities.
In fixed tint lenses, the shade of the lens does not change. There are two main types of fixed tint lens: classic lenses, which are coloured with a pigment to obtain the desired level of shading; and hi-tech lenses, which contain a polarized coating and therefore offer full glare protection as well as shielding against bright light.
Around three-quarters of lenses on the market have a classic fixed tint . The range of these tints is extremely large, giving you plenty of scope for expressing your personality, while also providing lenses adapted for specific activities such as sports.
A number of different methods are used to make classical fixed tint lenses, but they all involve adding a coloured pigment, which can be made light or dark or anywhere in between. This means fixed tint lenses come in a whole range of shades to suit different intensities of sunlight.
The tint of a lens is also responsible for shaping your perception of colours. Different tints filter different elements of visible light, meaning you may see ‘more yellow’ or ‘more blue’, for example. For everyday use, the best choice is a neutral (grey or grey-green) or all-purpose tint (brown). For sports, you may consider a yellow-orange tint, as this helps improve contrast. Blue blocker tints, meanwhile, completely filter out blue light, which has been linked to certains forms of eye damage. Most browns lenses are blue blockers.