These bifocal contact lenses can be manufactured in both rigid gas permeable (GP) materials and soft materials. Some bifocal contact lenses can be worn on a disposable basis which means that you have the freedom to choose to have the convenience of throwing the lenses away at certain intervals (and in some cases, even daily) and replacing those contact lenses with fresh and new ones.

Some bifocal contact lenses can be manufactured as soft multifocal contact lens made of silicone hydrogel material. This type of lens is FDA approved and can be worn up to 30 days of continuous wear. These bifocal contacts lenses have 2 prescriptions in the same lens. They are Alternating Bifocal Contact Lenses and Concentric Ring Designs.

The Alternating bifocal (or translating bifocal) functions much like bifocal eyeglasses because they have two power segments with a line of separation between the distance corrections on top and near below. With bifocal eyeglasses, this type of mechanism is effective because the said lenses stay in its proper place even as you move your eyes, which can happen with contact lenses, too. Given that most alternating or translating bifocals are rigid permeable (GP) lenses, they are usually smaller in diameter than the soft lenses and these lenses are positioned on your eye above your lower eyelid. As a result, when your eyes shifts downward, the lens stays in its proper place letting you to see through the lower near correction part of the said lens.

The Concentric Ring Designs type of bifocal contact lens is characterized by a prescription in the center and one or more rings surrounding it. In general at least two rings are within our pupil area but this may vary as our pupil expands and contracts due to varying light.

Prescription contact lenses are valid for a minimum of one year or the minimum required by every state law whichever is higher. You cannot buy additional lenses until your Optometrists give you an updated prescription when your first prescription given expires. You have the right to get a copy of your prescription after you undergo the eye examination.

The parameters specified in a contact lenses prescription may include:

1. The Materials Used.

a. Soft contact lens- are made of pliable hydrophilic plastics called hydrogels and can be processed by either a lathe cutting process or an injection molding process.

b. Rigid gas permeable contact lens- are made of oxygen-permeable plastic polymers containing silicone and fluorine.

2. Base Curve Radius. It is a parameter of a contact lens that show how much the lens should curve to match your cornea’s back curvature. Contact lenses must fit well to the wearer’s cornea in order to be comfortable and to facilitate tear exchange and oxygen transmission.

3. Diameter. It is how far in millimeters it is across the lens from one edge to the other.

4. Power in dioptres – Spherical, Cylindrical and/or reading addition.

5. Cylinder Axis. This is necessary if your lens correct for astigmatism.

6. Center thickness (CT)

7. Brand. Prescription contact lenses may indicate a specific brand.

When choosing a coloured contact lens, it is important to keep in mind that there are two major types of coloured contacts- the enhancement color lenses and opaque lenses.

Enhancement color lenses are intended for people with light eyes who wants to make their eyes brighter than the original color. For instance, a green-eyed person might select a blue enhancement tint in order to have most beautiful aqua eyes.

Opaque contact lenses are for people who have whether a light or dark eyes that wants a complete change of the color. Some color options include black, blue, green, white and more. The latter is best for those seeking a dramatic change in appearance.

Color Choices for People with Light/Medium Skin, Light Hair and Light/Dark Eyes

If you have a green eyes and want to enhance the natural color- sea green, emerald green, or aquamarine is your best choice. Pacific blue, ocean blue or aquamarine for blue eyes.

But if you want a dramatic color change for your green, blue, brown and hazel eyes, you may select from hazel green, jade green, pacific blue, pearl gray, pure hazel, sapphire blue, true sapphire, turquoise and warm honey.

Best Coloured Contact Lens for People with Dark Eyes and Dark Skin

You may select from amethyst, true sapphire, brown, sapphire blue, green, black and warm honey to dramatically change your natural green, blue, brown or hazel eyes color. And eden, moonlight, autumn and sunrise for illumination effect of your green, blue, brown or hazel beautiful eyes.

It is recommended to start with enhancers which make your eyes appear brighter but don’t change the natural eye color if it is your first time to wear coloured contact lens.