Prescription Lenses are available in Glass, Plastic CR39, & Polycarbonate materials. We strongly recommend the use of Polycarbonate Lens for safety eyewear. Polycarbonate is the most impact resistant lens material available in the market today & offers significantly greater impact resistance than Glass or Plastic CS-39 lenses.

Polycarbonate material is manufactured differently from the way that other lens materials are fabricated. An enormous amount of pressure is used to compress the raw material. The resulting product holds up so well under impact not because it is hard and unyielding, but rather because it is flexible and gives slightly under pressure without breaking. Polycarbonate lenses are actually constructed out of material that is identical to what is called "bulletproof glass." Polycarbonate has also been used for astronaut helmet shields and space shuttle windshields.

Features & Benefits:
High Impact Resistance - Studies have been made detailing exactly what happens when an object traveling at high speed meets a polycarbonate lens versus a traditional plastic lens. Using film that is slowed down and viewed frame by frame, one investigation demonstrated that a fast-moving ball coming into contact with a plastic lens broke the lens and impacted the eye. In contrast, the same ball traveling at the same rate of speed impacted the polycarbonate lens and flexed the lens but did not break it.

Lightweight - 1/2 the weight of conventional glass lenses; up to 30% lighter than Plastic CR39. In fact, polycarbonate lenses are sometimes referred to as featherweight lenses.

Ultraviolet (UV) Protection - A built-in UV block that won't rub or wear off. Protective wearer's eyes from more than 99% of harmful UV rays.

Scratch Resistance - The flexibility or softness of the lens material dictates that a scratch resistant coating be applied to the front and back surfaces of polycarbonate lenses. Manufacturers automatically coat them, and fabrication laboratories add a scratch resistant coating to any uncoated lens surface before sending the lens to a dispenser. So any polycarbonate lens you buy already has built-in scratch resistance.
 

LENS DESIGN

Ophthalmic lenses are available in variety of style. In the simplest of forms, lens styles are available in Single Vision and Multifocal powers.

Single Vision lenses have the same focal power throughout (top to bottom) and can be used to correct nearsightedness, farsightedness, astigmatism, or a combination of these disorders. Most people who wear glasses before the age of 40 have single vision lenses.

Multifocal lenses allow you to focus through different prescriptions for different distances through the same lens: essentially, more than one point of focus, hence the term "multifocals." With multifocal, available in Bifocal & Progressive additional lens designs.

Bifocals - meaning a lens with two points of focus, usually one for distance and one for near. A small portion of the bifocal eyeglass lens is reserved for the near-vision correction. The rest of the lens is usually a distance correction, but sometimes has no correction at all in it, if you have good distance vision. Generally, you look up and through the distance portion of the lens when focusing on points farther away and look down and through the bifocal segment of the lens when focusing on reading material or detail work up to about 18 inches away.

                                  
  Executive Bifocal                  Flat- Top Bifocal                    Round Bifocal 
        The blue section is for near / close vision ( Additional power ).
 

Progressive lenses, sometimes referred to as no-line bifocals, not only provide visual correction for distances that traditional bifocals can't, but they also hide the fact that you even need reading glasses.     

Progressive lenses are the closest to how natural vision is that you can get in a pair of prescription eyeglasses. They are more than just a defined near and distance correction in one lens. Rather, progressives provide a smooth transition from distance through intermediate to near, with all the in-between corrections included as well. This constant graduation of the prescription means that you can look up to see in the distance, look ahead to view things such as the computer in the intermediate zone, and drop your gaze downward to read and do fine work comfortably close up.     

          
         Design of Progressive lens - no line bifocal, provide the wearer with 
         distance, intermediate & near viewing without visible "segment"
         showing on the lens.

  OTHERS....

Anti-reflective coatings (A-R coating) are metallic oxide coating that are vacuum-applied to the lens surface to reduce reflections from lens surface and eliminate reflections from the back. This reduced amount of reflection enhances the appearance of the glasses and also allows more light to pass through the lenses, which can improve vision in low-light situations. Anti-reflective coating also provide some protection from scratching.

Tinted Lens is another option in colored lenses is a tint, which remains constant at all times. Tints are available on polycarbonate lenses and can be had in almost any color of the rainbow.

  How do you read eyeglass prescription?

A prescription for eyeglasses contains the powers for the lenses of each eye (including a reading addition if necessary), information on the separation of the lenses, and sometimes special requirements such as types of tinting, coating and so on.

Although each eye doctor writes a prescription in a somewhat different way, it usually contains the same elements. The lens correction for nearsightedness is indicates by the minus sign ( - ), while a plus sign ( + ) indicates farsightedness. Cylindrical lenses for astigmatism are designated by cyls, cx, or ( x ).

Let's analyze the following prescription:
 

	Sphere	Cylinder	Axis	Add	PD	Fit. Hgt
R	-3.00	-2.00	x  180	+1.50	33	16
L	-450			+1.50	32

The 'R' & 'L' indicate the prescription for the Right eye & Left eye respectively.

For Right eye: the  ' -3.00 ' in the Sphere column means that the patient has -3.00 diopters of nearsightedness. Cylinder column ' -2.00 '  means that the patient also has -2.00 diopters of astigmatism at axis 180 degrees.

For Left eye: the '  -4.50 ' means the patient only have -4.50 diopters of nearsightedness & no astigmatism.

The 'Add +1.50 ' indicates the power of bifocal addition, also means that the patient has 'see near problem'. (Pls refer Multifocal lens for more details.)

The PD ' 33 / 32 ' is a measurement of the distance between the pupils, a necessary measurement for ensuring a proper fit for the glasses.

The Fit. Hgt (Fitting Height) at ' 16 ' is also a measurement of division for Far & Near vision on the lens. This measurement must be taken from the wearer's frame.