Contact Lens Exam at Lone Star Vision in Plano and Celina, Texas
Contact lens exams differ from traditional eye exams because your ophthalmologist must not only determine the extent of your vision problem but also measure the shape of your eyeball. The diameter and curvature of your cornea is assessed using a kerometer, a diagnostic tool that is particularly useful for evaluating the axis and severity of astigmatism, Your doctor may also use a biomicroscope or slitlamp, to more closely examine the cornea, retina and aqueous humor of the eye if any abnormalities are suspected .
Your contact lens exam may also include a non-invasive imaging procedure called photokeratoscopy, or corneal topography, which maps the cornea’s surface curvature dimensions. Gaining a correct topographical image of the cornea is critical for correctly diagnosing corneal health and vision quality since the cornea supports about 70 percent of your eyeball’s refractive power. In addition to precisely gauging the fit of contacts, corneal topography is also used in planning LASIK, intraocular lens and cataract surgery.
Who are Good Candidates for Wearing Contact Lenses?
Contacts can help correct numerous vision issues such as near-sightedness, farsightedness, presbyopia (when bifocal or tri-focals are needed) and astigmatism. Following your contact lens exam, your ophthalmologist will tell you whether your eyes are healthy enough to wear contact lens, write your prescription and answer any questions you have about wearing contact lenses. Very few people cannot wear contacts lenses–only those with serious systemic diseases or eye disorders are unable to be fitted for contact lenses.
If you are diagnosed with presbyopia, our ophthalmologist may prescribe monovision lenses that use the “better” eye for distance vision and the less capable eye for nearer vision. In other words, different lenses are fitted for each eye so that vision correction is applicable to unique vision measurements taken from each eye. Monovision corrective lenses work better for some people who have worn bifocals at one time and found them difficult to get used to or simply not effective.
Information Contained in a Contact Lens Prescription Given by Our Celina and Plano Optometrists
A complete contact lens exam provides an ophthalmologist with the parameters necessary to prescribe correctly fitting and functioning contact lenses. Parameters include your corneal diameter, base curve radius, center thickness of the cornea and your precise refractive error (expressed in a measurement called a diopter). Diopters indicate how much your contact lenses must be able to bend light so that the light focuses on the retina and allows the retina to normalize vision problems.
Why a Contact Lens Exam is Necessary and Good for Your Overall Health
Abnormalities detected within the retina, such as ballooning or narrowing of blood vessels can provide our ophthalmologist with early warning signs of possible health issues ranging from diabetes and hypertension to heart or kidney disease. In addition, getting regular eye exams at Lone Star Vision is essential to keeping your eyes healthy and ensuring your contact lenses are performing as optimally as possible to effectively correct your vision.