Listed below are the most common lens designs. Many other designs are also available. Dr. Akamine Davidson and her staff will discuss options with you during your exam, to help determine which designs will meet your visual and aesthetic needs.
Single Vision Lenses – These are lenses with the same power throughout the entire lens
Zeiss Individual Personalized Single Vision Lens
The Individual Single Vision lens is precisely personalized for your eyes to give you the clearest, most panoramic vision possible. The Individual is recommended for prescriptions over 2 diopters or with those with astigmatism.
With the use of iTerminal (see section on iTerminal), we can take many precise measurements such as the distance the between your eyes, the distance your glasses are from your eyes, the tilt of the glasses, and the horizontal and vertical measurements of the frame. The actual prescription in the glasses is then re-calculated for each portion of the lens to compensate for the power change as you look through different sections of the lens.
The lens is then coated on both surfaces with PureCoat, the newest, clearest and most scratch-resistant anti-reflection coating. PureCoat eliminates reflections from the lens to give you the clearest, crispest vision possible. The result is that the PureCoat delivers a vision experience unlike any seen before!
Bifocal Lenses – Lenses with 2 powers in them. One on the top, usually for distance viewing and a different power on the bottom, usually for reading. The prescription in the lens can be modified for different applications, such as computer vision and reading. The bifocal area comes in several sizes: 25mm, 28 mm (most common) and 35mm (for the largest reading area) across the bifocal line, or a rounded line 22, 25 or 28 mm in diameter. (this line is almost invisible)
Trifocal Lenses- Lenses with 3 powers in them; one on top usually for distance viewing, one in the middle for intermediate distances and clarity at arm’s length, and the bottom for reading vision.
The trifocal are comes in several sizes, 7mm deep x 28mm wide or 8mm deep x 35mm wide. Other occupational lenses are also available such as a 12mm deep and 35mm wide for maximum computer viewing; Double-D with the intermediate power on the top and the reading on the bottom, with the distance power in the middle. Good for mechanics, librarians, pharmacists, or anyone who needs to see at arm's length above their head.
Progressive Addition Lenses – These lenses most closely mimic your natural vision. The distance vision is in the top and as you gradually lower your eyes to read, the lens “progressively” gets stronger. So you see clearly at every distance from distance, to the computer, to reading. These lenses do not have a line.
These lenses have been greatly improved through the years to give you clearer vision. The original designs are still available as inexpensive options, but the newer lenses allow wider, clearer vision at all distances.
Many stores that provide “discount” or “bargain” lenses which use these older designs. Although they serve the purpose, they do not give you the widest, clearest vision available. We prefer to use the latest technology in order to provide you with optimum vision at all distances.
Zeiss Individual Personalized Progressive Addition Lens
The Individual Progressive lens is precisely personalized for your eyes to give you the clearest, most panoramic vision possible. With the use of iTerminal, we can take many precise measurements such as the distance the between your eyes, the distance your glasses are from your eyes, the tilt of the glasses, and the horizontal and vertical measurements of the frame. The actual prescription in the glasses is then re-calculated for each portion of the lens to compensate for the power change as you look through different sections of the lens.
The lens is then coated on both surfaces with PureCoat, the newest, clearest and most scratch-resistant anti-reflection coating. PureCoat eliminates reflections from the lens to give you the clearest, crispest vision possible. The result is that it delivers a vision experience unlike any seen before!
LENS TECHNOLOGY OPTIONS
Listed below are our most popular lens treatments. There are many others. Dr. Akamine Davidson will discuss them with you during your examination to determine which would be the most appropriate for your visual needs.
PureCoat Anti-Reflection Coating – Anti-reflection coatings eliminate the reflections of light from the surface of the lens allowing for clearer, crisper vision. If you were looking through your windshield at night, you might be able to see. However, if you were to open the window to look outside, everything would be much clearer. That is because you are not looking through glass that has all of the reflections on it. The anti-reflection coatings eliminate the reflections on the lens, allowing you to experience clearer, crisper vision.
PureCoat has a base layer that is rated the hardest, most scratch resistant coating on the market. Also part of PureCoat are multiple, microscopically thin layers of anti-reflection material, which are added to the lens. The result is an extremely clear lens, which is very difficult to scratch.
Not all anti-reflection coatings are created equal. The inexpensive, lesser quality coatings are only applied to the front surface of the lens and will smudge with oils, are difficult to clean and will peel or scratch easily, thereby degrading your vision. We always use the industry’s best coating and warranty it against scratches or defects for a year.
Transitions- Transitions is a photochromic lens technology, which means that it is clear indoors and at night, and when exposed to UV light from the sun, darkens. The lens darkens very quickly and takes a few minutes to clear once you come out of the sun.
These lenses are very convenient for many people who just desire to have one pair of glasses for indoor and outdoor use. Because the windshield of the car blocks most of the UV rays from the sun, the lens does not always darken as much as some people desire, while they are driving with the windows closed. For extended driving or a need for darker lenses, we recommend a second pair of polarized lenses.
Polarized Lenses- Polarized lenses block more glare than tinted lenses. When light hits a flat surface and is reflected off of that surface, the light becomes polarized. That means that all of the wave lengths of light go in the same direction. The polarized lens blocks all of the reflected light, plus the tint of the lens uniformly blocks up to 80% of the light entering the eye. So there is enough light to see, but not too much light to cause glare. We highly recommend polarized lenses for every pair of sunglasses we sell.
Listed below are the most common lens materials used. There are other materials available and Dr. Akamine Davidson can discuss them with you during your examination to determine which would be best for your visual needs.
CR-39 or Standard Plastic Lenses – Lenses made of standard plastic are lighter in weight than glass. In powers over +/- 2 diopters, the lenses can start to get thick and heavy. So lighter weight, thinner plastics are recommended. These lenses can be treated for scratch resistance and UV absorption as an add-on feature.
Polycarbonate Lenses – Polycarbonate lenses are thinner and lighter than standard plastic lenses. Polycarbonate lenses also inherently absorb UV radiation and are impact resistant. They are pre-treated with a scratch resistant coating. This is our lens material of choice.
High Index Lenses – There are several grades of high-index lenses. High-index refers to the index of refraction which is a measure of how much light is bent when going through different types of plastic. The higher the index of refraction, the more light is focused. Therefore, the thinner the lenses become. In the higher prescriptions, over 3 diopters, high index lenses make a big difference. If you have a high prescription and decide to go with high index lenses, you'll be amazed at how thin and attractive your new glasses will be.
Glass Lenses – Glass lenses are not commonly prescribed anymore because they can break and shatter causing serious eye injury. Many people like glass lenses because they don't scratch as easily. With our new scratch-resistant coatings like PureCoat we can create a lens that is just as scratch resistant as glass while providing you with a lighter and clearer pair of glasses with a one-year warranty.
During fabrication, glass lenses must be treated for impact resistance. Then, they are tested using the “drop-ball test,” which is a steel ball dropped onto the lens from one meter away. If your lenses fail this test, delivery of your glasses may be delayed. But the good news is the pair that arrive will be highly impervious to scratches...even by a dropped metal ball.