The Steps Involved In Contact Lens Fitting

Contact Lens Fitting : switching from glasses to contacts is a great way to change your appearance, gain self-confidence and avoid all the negatives of wearing glasses on a regular basis.

Contact lenses have really changed through time and instead of the old glass types that were very irritating to the eyes there are now other options in both rigid and soft contact lenses.

The newest type of material, silicone hydrogel, is both oxygen permeable and comfortable, making extended wear or daily wear for contacts an option for many people.

When you first arrive at the optometrist's office he or she will examine your eyes and sight and determine a prescription to correct the vision problem. This can include common vision problems such as myopia (short sight), hypermetropia (far sight), astigmatism (irregular shape or inability to focus) or presbyopia (inability to focus typically seen with aging).

However, this is just for the vision and you will still have to have additional measurements and tests on your eye. One of the most important tests the eye doctor will complete for contact lens fitting is to determine the exact shape of the front surface of the eye.

This is a very precise measurement that is completed with a specialized optometric tool known as a keratometer which actually focuses in on the shape of the eye at the apex of the cornea.

Now, with computer technology, the surface of the eye is scanned by a computer camera and then recreated in a 3-D graphic within a specific computer program. This actually develops a working model of the exact surface of your eye.

Another test is also completed, sometimes before the actual measurement is done, to gain an understanding of the tear film on your eyes. If you have dry eyes or a thin tear film contacts may not be a good option, even with all the new materials available.

Once this test is completed and the basic shape of your eye is charted, the optometrist will try out different contact lenses to evaluate their comfort level and correctness of fit. A biomicroscope is used to carefully check the shape of your eyes with regards to the fit of the trial lenses.

You will often be required to wear these lenses for awhile, plus you will have to blink, close your eyes and look around to ensure that the lens continues to sit properly on the surface of the eye.

Once that is done you have completed your contact lens fitting and are ready to get the prescription filled.

Most people without any type of astigmatism or irregularity of the eye shape will use a spherical contact lens. Spherical lenses simply form a sphere shape on both in inner surface and the outer surface. For those people that have irregularities in the shape of the eye a toric lens is used.

The toric lens is a combination of a sphere shape and a cross section of a cylinder or a more donut shaped lens. This allows the contact to correct for the irregular vision in the eyes based on the shape of the eye itself. Some people may have a spherical contact for one eye and a toric lens for the other; this is not at all uncommon.