PRODUCT INFORMATION
Eyeware Lenses
Material
Normal Index Value :-
Standard Plastic CR-39 Lenses :
These are conventional plastic material lenses with a refractive index of 1.498 that have been widely used since their introduction in 1947. One of the biggest advantages of this lens is its affordability. It also provides good optical clarity and is easy to tint. Some disadvantages of this material are that it scratches easy, does not provide adequate UV protection, is not as impact resistant as other lenses and is also heavier and thicker than the higher index plastics. It should be noted however, that a scratch resistance coat, as well as a UV coating can be applied to the lens helping to reduce some of these deficiencies. CR-39 plastic lens material is usually only recommended for those with a weak prescription where lens thickness and weight are not a concern and for dress eyewear in which safety is not an issue.
CR-39 lenses have a high Abbe value of 59.3 making them the lenses with the least distortion from dispersion/chromatic aberration.
Mid Index Value :-
Polycarbonate Lenses :
Polycarbonate lenses have a higher index of refraction (1.586) than CR-39 plastic (1.498) and are therefore thinner in an equal lens prescription. With a higher index (of refraction), light is bent more efficiently, therefore it requires less material to achieve the eyeglass prescription making the lenses much lighter. Another significant advantage of these lenses is that they are impact resistant. Polycarbonate lenses offer up to 10 times more impact resistance than regular plastic lenses, hence along with Trivex, are the lenses of choice for safety glasses, children’s eyewear, and for anyone who wants durable yet thin lenses. It’s important to recognize that impact resistant does not mean shatterproof. They can still break, therefore official safety glasses should be worn for eye-hazardous jobs and sports. Additionally, Trivex and polycarbonate naturally block most UV light (385 nanometers and below) and do not need the application of a UV coating. They are also lab favorites for use in rimless frames, because polycarbonate lenses can be easily drilled and resist cracking around the drill holes. A disadvantage of polycarbonate is that it is naturally a soft material causing it to scratch much easier. However, unlike CR-39 basic plastic lenses, a scratch resistant coating is almost always standard as it is applied when the lenses are made. With higher refractive indexes, there are often more chromatic aberrations, meaning visual disturbances of light, that can be interpreted as blur by some. Chromatic aberrations are higher in polycarbonate lenses. The abbe value of polycarbonate is 30, the lowest of all lens materials making it the worst lens for optical clarity and integrity. Plenty of people cannot adapt to a polycarbonate lens. For those reasons Trivex is the better choice in a mid-index lens.
Trivex Lenses :
Trivex is a relatively new optical lens material. It has the ultraviolet blocking properties (380 nanometers and less) and shatter resistant properties of polycarbonate. However, Trivex lenses have a much higher abbe value (43-45) vs. polycarbonate (abbe value 30) making it much better in optical clarity with fewer chromatic aberrations. Trivex also has a slightly lower density so it is lighter than polycarbonate. In fact, Trivex is the lightest weight lens material available. Another advantage that Trivex has over polycarbonate is that it can be easily tinted.
Trivex along with polycarbonate is great for rimless frames and those frames requiring drill mount screws through the lenses.
High Index & Ultra-High Index Value Plastic Lenses :-
MR7, MR8 & MR174 :
An even higher index lens should be considered to achieve the thinnest lenses possible. This means the index of refraction would need to be greater than that of polycarbonate and Trivex (>1.60). High index lenses are classified by numbers that represent their refractive index and range from 1.64 to 1.74. High index lenses can be up to 50% thinner than regular glass or plastic lenses, and they’re usually much lighter, too. Although these lenses are generally recommended for people with high optical prescriptions, high index lenses can benefit anyone who would like a thinner lens profile. The higher the index, the thinner the lens will be relative to basic plastic. One of the biggest disadvantages of high index materials is the higher cost compared to other materials including polycarbonate and Trivex. High index plastics also have a lower abbe value (32-42) and therefore have some problems with chromatic abberations. Because of the way that light interacts with high index lenses (chromatic aberrations), it’s highly recommended that an anti-reflective (AR) coating also be applied to the lens to help with reflected light.
Because of the density of the high index plastic material it isn’t usually the lightest material even though it is thinner. Trivex is usually the lightest weight lens material.
High index plastics do offer good ultraviolet inhibition (below 380-400 nanometers) properties as well as shatter resistance.
A lens with a higher index of refraction tends to reflect light more than standard CR-39 plastic or glass lenses. The extra reflections are usually quite bothersome for the wearer especially at night and while using a computer monitor. The glare from the lenses is also cosmetically unappealing. Because of this most high index lenses come with an anti-reflective coating as a standard option.
Glass Lenses :-
Glass lenses provide excellent optics, the most scratch resistant lens material and blocks UV light. However, glass lenses are heavy, thick and dangerous if broken and cannot be used in certain frame styles. Some glass is available with a refractive index as high as 1.8 and 1.9.
Coatings
Anti-Reflective Coating :
An anti-reflective coating, also known as AR or anti-glare coating, is an extremely thin multilayer coating that gets rid of reflections from the front and back surfaces of lenses. This coating makes your lenses almost invisible so people can look into your eyes without seeing their reflections from your glasses. It eliminates glare caused by light reflecting from your lenses. Without these reflections, you can see more clearly and drive more comfortably at night.
An AR coating is especially ideal for polycarbonate and high-index lenses, which reflect more light than standard glass or plastic lenses. This coating also works well for aspheric lenses since they have flatter curves than regular lenses, causing more noticeable reflections.
To ensure comfort in all lighting conditions, eye care professionals recommend applying an anti-reflective coating to photochromatic lenses. It improves light transmission through the lenses for night driving and reduces glare in bright sunlight.
Scratch-Resistant Coating :
There is no such thing as completely scratch-proof eyeglass lenses. However, lenses with a scratch-resistant coating feature a harder surface that’s more resistant to scratching. This type of coating is beneficial for kids’ lenses as it improves durability. Most eyeglass lenses today, including high-index lenses and polycarbonate lenses, have a built-in scratch-resistant coating.
In some cases, scratch-resistant coatings are optional, so make sure to inform your eye doctor that you want your lenses to have this coating for added durability. Don’t forget to ask about the warranty on eyeglass lenses that include a scratch-resistant coating.
While a scratch-resistant coating makes your glasses more resistant to impact, it doesn’t provide complete protection against wear and tear. To keep your glasses in good shape, store your them in a cushioned case when not in use and clean the lenses using a microfiber cloth. You also need to be careful with products that claim to repair scratched lenses. While they may fill in the scratches, they can’t make the scratches disappear to restore the appearance of the lenses.
UV Coating :
UV exposure has been linked to age-related eye problems like cataracts and macular degeneration. Lenses that block 100 percent of UVA and UVB rays can help in preventing the damaging effects of UV radiation.
Fortunately, almost all high-index plastic lenses and most sunglasses have 100 percent UV protection built-in. However, CR-39 plastic lenses require an extra coating for total UV protection. Eyeglasses with photochromic lenses also block 100 percent UV rays without the need for an added UV lens coating.
Photochromic Treatment :
Photochromic lenses, also called transitions, automatically darken when exposed to sunlight and become clear when you go back indoors. These lenses are available in all materials and designs. You should consider them if you don’t want to purchase another pair of prescription sunglasses or if you have light sensitivity.
Keep in mind that photochromic lenses darken and lighten to varying degrees. Some brands take longer to change than others. Discuss your needs and options with your eye doctor.
Mirror Coating :
A mirror lens coating prevents light from reflecting into the eye. It makes the outside of the lens look like a mirror, but wearers don’t see the mirror coating from the inside of the lens. Only the color tint of the coating is visible.
These coatings are available in various colors, densities and styles. They are popular in both prescription and non-prescription sunglasses. Mirror coatings can be applied as a solid, gradient and double gradient coating.
Two of the most common mirror coatings are the flash mirror and half mirror. The half mirror creates a full mirror reflection on the outside of the lens while completely concealing the eye. On the other hand, the flash mirror coating is less dense and gives a transparent mirror look. Consult your optometrist to find out which option is best for your vision needs.
Anti-Fog Coating :
In the cold months, it can be frustrating when your glasses constantly fog up every time you step outside. Fogginess limits your ability to see, which can be dangerous, especially when you’re outdoors or driving. This is even more dangerous for police officers and people who respond to emergencies.
If you wear eyeglasses and participate in sports activities, your lenses may also fog up when you’re hot and sweating. Fogging occurs when tiny droplets that form by condensation on the lens surface are cooler than the surrounding air temperature. Fortunately, a permanent coating exists to eliminate fogging. This factory-applied coating prevents condensation in lenses, eliminating fogging.
Tinted Lenses :
Lens tinting can help with certain vision problems and can also improve the appearance of your glasses. Some tints help with computer use and can even lead to better sleep. Blue-light blocking lenses claim to ease eye strain and discomfort while in front of a computer. A yellow tint may increase contrast and a gray tint may not change color perception in sunglasses.
By undergoing eye exams, you can find out what the right lens tint for your needs would be. However, if you don’t have any underlying health need for tinted lenses, the color choice is up to you. Wearing tinted glasses has no direct side effects, but some may experience an adjustment period. For some, it affects their accurate color perception.
Tinted lenses that are too dark pose certain risks if regularly worn indoors. As your eyes start to get used to the darker view, they become more sensitive in brighter lighting conditions. Lenses with at least 50 percent visible light transmission are better for indoor wear.
Eyeware Frames
Frames Styles and Shapes
Rectangle Glasses :
Rectangle glasses are a staple of the frame world for a reason: they’re almost universally flattering. Their lenses are wider than they are tall, with even, straight borders and rounded corners. They’re a simple, sophisticated, and reliable shape, but you can give them as much pizzazz as you like with bold colors.
Square Glasses :
More angular than their rectangular cousins (say that five times fast), square glasses have lenses with approximately equal height and width. Their boxy shape can add some edge to soft, rounded facial features. This shape is bold with old-school appeal.
Round Glasses :
For such a simple shape, the circle takes a certain amount of confidence to pull off. Round wire glasses have an authoritative, charmingly vintage vibe, whereas thicker acetate frames carry a more fashion-forward spirit. This is a style that’s instantly memorable, but also one whose singularity should be respected—try these glasses on at home if you’re not quite sure how they’ll look on you.
Cat-eye Glasses :
The epitome of understated glam, cat-eye glasses have upper corners (the ones nearest your temples) with an upswept shape, almost as though they’re implying thick eyelashes. Their distinctive, curvy browline has led them to be characterized as a feminine glasses style, but rest assured, anyone can wear cat-eyes to great effect.
Aviator Glasses :
Aviator glasses are also known as pilot glasses. In their earliest incarnation, they were tinted sunglasses worn by military pilots. However, their broad lenses and bar-over-the-nose-bridge design eventually took off (pardon the pun) amidst the general public. Now they’re available as a style of regular prescription glasses as well as sunglasses.
Oval Glasses :
A bit more wide than circular frames, and more rounded than rectangular ones, oval glasses have a smooth, chic look that can play well with sharper or more angular features. Their frames can be thick or wire-thin, making them an attractively flexible option for wearers.
Browline Glasses :
Browline glasses, faithful to their title, have frames that outline the brows and leave the bottoms of the lenses largely rimless or with thinner outlines. They’re associated with an academic, stoic kind of style, and were hugely popular in the 1950s.
Geometric Glasses :
Geometric glasses embrace the shapes that others don’t—hexagons, octagons, rounded bottoms with angled tops, and a host of others. If the lens borders have more than four distinct sides, or a shape that just isn’t easily categorizable, then they’re probably geometric frames. This glasses style is for anyone who truly wants to stand out in a crowd.
Oversized Glasses :
Oversized glasses aren’t limited to a single frame shape. As their name implies, their distinguishing feature is that they’re quite large, and therefore they aren’t as ubiquitous in stores. They’re not always novelty items, though—their big lenses provide a broad field of vision, and their size makes them striking accessories for the fashion-forward set.
Rimless Frames :
For a more subtle look, you may prefer rimless frames. They have no rims around the lenses. Instead, the temples and the nose bridge connect directly to the lenses themselves. This means there is less material in front of your face.
People like this low-profile style for its minimalism. There tend to be fewer shape options, but you can find a few options for materials and colors. Additionally, some rimless frames cannot accept every type of lens. So, if you need something other than single vision lenses, make sure to check the product info to ensure it can accept your lenses.
Materials
Plastics :-
Acetate frames/Zyl frames :
The most used material when it comes to quality designer frames is definitely acetate. A high-quality plastic originating from the renewable resources of wood pulp and natural cotton fibers. Acetate retains its color brightness impeccably over time because its hue is embedded in the material rather than sprayed on which also prevents any color peeling. By mixing different colors of melted acetate, beautiful color combinations can be created, in layers (in all directions) or in swirls, giving it a turtle look, but in every possible color. When creating a frame out of acetate, a flat sheet of the material is sawn (either by hand or CNC) into the design of the frame and then heat-shaped to add curve and inclination.
Nylon frames :
This frame material is mostly used in cheap sunglasses. Nylon is strong, lightweight, and flexible, but it can become brittle with age. For this reason, it has for the most part been replaced by nylon blends – polyamides, copolyamides and gliamides – which are more durable.
TR90 Nylon frames :
TR90 was produced through Swiss technology as a thermoplastic material that is incredibly durable, flexible, and lightweight. Glasses made with TR90 are extremely comfortable because they have a flexible quality. Since they are flexible, they can bend under pressure and contour your face comfortably. This flexibility also makes TR90 glasses resilient to damage. Because the material is pliable, they are far less likely to break or bend from impact. If you’re guilty of constantly dropping your glasses, fear not! TR90 frames can prevail! Finally, and most remarkable of all, TR90 glasses are supremely lightweight! Even the boldest, biggest styles don’t feel bulky when made with TR90. The thermoplastic material has a barely-there feel that you truly have to wear to believe.
Ultem frames :
ULTEM resin is a flame-retardant, high-performance thermoplastic. It features a high strength-to-weight ratio, excellent heat resistance, and high impact strength. This material is ultra-lightweight, durable, and heat resistant up to 400⁰. Ultem frames can weigh only 1/3 of the weight of traditional plastic or metal frames.
Metals :-
Titanium frames :
One of the most important aspects of keeping an eyeglasses frame is its durability. No matter how carefully you use your eyewear frames, they are bound to break or fall. Most Eyeglasses are made up of Metal and Plastic Material which are commonly used in the manufacturing of eyeglasses frames. But these materials can deform easily if used for a very long time. People started choosing titanium material over metal and plastic in eyeglasses because these frames can be bent and twisted and then come back to its original form. The quality of these frames is durable and reliable for rough use also. People who opt for titanium frames also do not have to be bothered about carefully handling them as these are impact-proof.
As compared with regular metal, titanium is one of the lightest and most preferred materials used in the manufacturing of eyeglass frames. These titanium frames can be easily worn with a lot of comfort and relief while playing games, jogging or running. With no maintenance required for these frames, it is surely one of the best materials, especially for eyeglasses frames
Flexon frames :
This is a titanium alloy composed of roughly 50% titanium and 50% nickel. Frames made of memory metal are extremely flexible and can be twisted or bent to an extreme and still return to their original shape. This feature makes memory metal frames great for kids or anyone who is hard on their glasses.
Beta titanium frames :
This is an alloy of predominantly titanium, with small amounts of aluminum and vanadium. These other metals in the alloy make beta titanium more flexible than 100% titanium for easier fitting adjustments. Beta titanium has memory features and is mostly used in high-quality designer frames. Due to it toughness and low weight, it can be used to create thick-looking frame fronts as well as ultra-thin eyewear temples.
Monel frames :
This popular, inexpensive material is an alloy of nickel and copper. It is less costly than other metals, but – depending on the quality of the plating used – Monel frames may or may not discolor and cause skin reactions over time. Many low-priced metal frames would be made out of Monel.
Beryllium frames :
This lower-cost alternative to titanium resists corrosion and tarnishing, making it an excellent choice for anyone with high skin acidity or who spends a good amount of time in or around saltwater. It’s also lightweight, strong, flexible, and available in a wide range of colors.
Stainless steel frames :
Stainless steel frames and surgical stainless are an alternative to titanium. Qualities of stainless steel frames include lightweight, low toxicity and strength; many stainless steel frames also are nickel-free and thus hypoallergenic. Stainless steel is readily available and reasonably priced. It’s an alloy of steel and chromium, which provides excellent resistance to corrosion, abrasion, and heat.
Aluminum frames :
The most abundant metal in the earth’s crust, aluminum is a lightweight option for eyeglass frames. It is the most widely used non-ferrous metal in the world. In addition to its lightweight, aluminum is also highly corrosion-resistant, soft, and durable. Aluminum is also 100 percent recyclable. Aluminum can bend and be slightly less durable than other materials.
Gold frames :
Dense and shiny, gold is the most malleable metal on the planet. Because of its high cost, it is used sparingly in the manufacture of eyeglass frames. Worked into stunning silhouettes in some high-end eyewear collections, it is also used in more moderately-priced lines as an accent or plating.
Silver frames :
Solid silver or sterling silver is not used commonly as a principal frame material because it doesn’t make very wearable or comfortable frames. Sometimes silver is used as a trace element in metal alloy frames and often provides a jewelry-like accent on plastic frames.
One of the most important aspects of keeping an eyeglasses frame is its durability. No matter how carefully you use your eyewear frames, they are bound to break or fall. Most Eyeglasses are made up of Metal and Plastic Material which are commonly used in the manufacturing of eyeglasses frames. But these materials can deform easily if used for a very long time. People started choosing titanium material over metal and plastic in eyeglasses because these frames can be bent and twisted and then come back to its original form. The quality of these frames is durable and reliable for rough use also. People who opt for titanium frames also do not have to be bothered about carefully handling them as these are impact-proof.
As compared with regular metal, titanium is one of the lightest and most preferred materials used in the manufacturing of eyeglass frames. These titanium frames can be easily worn with a lot of comfort and relief while playing games, jogging or running. With no maintenance required for these frames, it is surely one of the best materials, especially for eyeglasses frames
Contact lenses
Contact lens designs
Spherical contact lenses :
Spherical contact lenseshave the same lens power throughout the entire optical part of the lens to correct myopia (nearsightedness) or hyperopia (farsightedness).
Toric soft contact lenses :
Toric soft contact lenses have different powers in different meridians of the lens to correct astigmatism as well as nearsightedness or farsightedness.
Multifocal contact lenses :
Multifocal contact lenses (including bifocal contacts) contain different power zones for near and far vision to correct presbyopia as well as nearsightedness or farsightedness. Some multifocal lenses also can correct astigmatism.
Cosmetic contact lenses :
Cosmetic contact lenses include color contacts designed to change or intensify your eye color. Halloween, theatrical and other special-effect contacts also are considered cosmetic lenses. A contact lens prescription is required for cosmetic contacts even if you have no refractive errors that need correction.
Extra Featured Contact Lenses :-
Bifocal contacts for astigmatism :
These are advanced soft contacts that correct both presbyopia and astigmatism, so you can remain glasses-free after age 40 even if you have astigmatism.
Contacts for dry eyes :
Are your contacts uncomfortably dry? Certain soft contact lenses are specially made to reduce the risk of contact lens-related dry eye symptoms.
Colored lenses :
Many of the types of lenses described above also come in colors that can enhance the natural color of your eyes — that is, make your green eyes even greener, for example. Other colored lenses can totally change the color of your eyes, as in from brown to blue.
Special-effect lenses :
Also called theatrical, novelty, or costume lenses, special-effect contacts take coloration one step further to make you look like a cat, a vampire, or another alter-ego of your choice.
Prosthetic lenses :
Colored contact lenses also can be used for more medically oriented purposes. Opaque soft lenses called prosthetic contacts can be custom-designed for an eye that has been disfigured by injury or disease to mask the disfigurement and match the appearance of the other, unaffected eye.
Custom lenses :
If conventional contact lenses don’t seem to work for you, you might be a candidate for custom contact lenses that are made-to-order for your individual eye shape and visual needs.
UV-inhibiting lenses :
Some soft contact lenses help protect your eyes from the sun’s ultraviolet rays that can cause catracts and other eye problems. But because contacts don’t cover your entire eye, you still should wear UV-blocking sunglasses outdoors for the best protection from the sun.
Scleral lenses :
Large-diameter gas permeable lenses called scleral contacts are specially designed to treat keratoconus and other corneal irregularities, as well as presbyopia. Myopia control contacts. Special contact lenses are being developed to slow or stop the progression of nearsightedness in children.
Contact lens materials
Soft lenses are made from gel-like, water-containing plastics called hydrogels. These lenses are very thin and pliable and conform to the front surface of the eye.
- Silicone hydrogel lenses are made of an advanced type of soft contact lens material that allows more oxygen to pass through the lens and reach the front surface of the eye. Silicone hydrogel contact lenses are now the most popular type of contact lenses.
Gas permeable lenses. Also called GP or RGP lenses, these are rigid contact lenses that maintain their shape on the eye, enabling them to correct astigmatism and other refractive errors. Gas permeable contact lenses typically are smaller in diameter than soft lenses and are made of highly oxygen-permeable materials. It usually takes some time for your eyes to adjust to GP lenses when you first start wearing them; but after this initial adaptation period, most people find GP lenses are as comfortable as soft lenses.
Hybrid contact lenses have a rigid gas permeable central zone, surrounded by a “skirt” of hydrogel or silicone hydrogel material. They are designed to provide wearing comfort that rivals soft or silicone hydrogel lenses, combined with the crystal-clear optics of GP lenses.
PMMA lenses are rigid contact lenses that look like GP lenses but are made of a plastic material that is not oxygen permeable. PMMA lenses were commonly prescribed years ago, but essentially have been replaced by gas permeable lenses.