Contact lenses are among the best options for vision correction available today, with over 45 million people in the United States using them. They do not change the appearance of your facial structure in any way like eyeglasses do, which is one of the leading reasons they are popular.
They also allow you to be more active and play sports without worrying about breaking anything. However, getting contact lenses is a complex process because of the different prescriptions and the fitting.
A contact lens exam differs from your comprehensive eye exam because it includes specific tests critical to finding the right lenses. The contact lens exam first involves a comprehensive eye exam where the eye doctor checks for your eyes' health. They also get the level of visual acuity from the comprehensive exam.
During the exam, the eye doctor will ask you about your lifestyle and any preferences you may have. This information helps them determine the ideal lenses.
The main aim of the exam is to ensure that the lenses sit comfortably on your eye surface. A poorly fitting contact lens can lead to various complications, some of which may lead to significant eye damage. Here are the main tests the eye doctor performs to ensure the fit of your contact lens.
The eye doctor will use a special keratometer to measure your corneal base curve during this test. It does this by reflecting light off the cornea's surface and examining the reflections that come off it. The keratometer is only used to measure the front of the cornea, a small area. They usually need a corneal topography test to measure a larger cornea area.
The eye doctor uses a corneal topography test to get a more detailed image of the entire cornea for more accurate mapping. It also uses light and measures the reflection of light to map the corneal surface.
The eye doctor will also measure the size of your iris or pupil, especially if you are considering using rigid gas-permeable lenses. This test could be manual as the eye doctor uses a card with different pupil sizes to estimate the size. They could also use an automated instrument that gives horizontal and vertical diameters.
This exam will check whether you have a healthy tear film to support regular lenses or need specialized lenses. Usually, people with dry eye need specialized lenses that prevent the worsening of their dry eye symptoms.
Poorly fitting contact lenses usually cause scratches on the cornea's surface, which could become severe. A corneal abrasion usually exposes the eye surface to bacteria that can cause infections or ulcers. These could lead to permanent damage, poor vision, or complete vision loss in the affected eye.
If the cornea fits too tight, it can lead to poor corneal nutrition that causes severe discomfort, called tight lens syndrome.
For more on the importance of a proper contact lens fitting, visit Eye Vantage at our office in Katy, Texas. Call (281) 771-1323 to book an appointment today.