What Does a Contact Lens Exam Entail?

Regular eye exams involve ocular health and visual acuity tests. These tests help your eye doctor at Smoot Eye Care to determine whether you need vision correction. Contact lens exams require more in-depth tests than these.

During this comprehensive exam, your optometrist may ask about your lifestyle. They may also inquire about your preferences regarding the kind of lenses you want. Your choices include rigid gas-permeable lenses, soft lenses, and multifocal or bifocal lenses.

Depending on your daily routine, you can opt for disposable lenses. They range from bi-weeklies, dailies, monthlies, or extended-wear contacts.

The Contact Lens Exam

Before your doctor can do anything, they must first take you through a consultation session.

Consultation

After the initial queries, the doctor will check for any underlying eye conditions. Some of them require special care when selecting the ideal type of lens. The size of the contacts must fit comfortably on your cornea.

If they do not, you may have blurry vision and corneal abrasions, among other issues. The next step involves measurements. Here are some that the doctor will need.

Corneal Size and Curvature

Your doctor has to run this test to confirm the size and base curvature of the contacts. They use a keratometer to perform the exam. The device beams at your cornea to measure its base curve. For a more accurate reading, they may also use a corneal topographer. Unlike the keratometer, it provides a color-coded minutia of your entire cornea.

Both devices help the doctor determine whether the irregular shape of your cornea is a symptom of astigmatism. If so, you may need a toric lens instead of traditional contacts.

Iris or Pupil Size

To determine the dimensions for contacts, the optometrist will need to measure the size of your iris or pupils. These are crucial for rigid gas-permeable lenses. The doctor will either use a ruler or card comprising various sizes of pupils. They will try to find the image that closest matches your pupils. Another way of doing this involves holding a pupil gauge near your eye to estimate the size of your iris.

Some doctors prefer to use an electronic instrument. It provides an accurate measurement of the pupil, plus its vertical and horizontal diameter. They may use other similar techniques to determine the same.

Tear Film Evaluation

Among the issues that affect the wearing of contact lenses is dry eyes. If you wear contacts with this condition, they will feel uncomfortable, dry, and itchy. Your doctor will have to perform a tear film evaluation exam. It involves placing a drop of aqueous dye into your eye. They then use a slit lamp to view your tears.

Alternatively, they may put a special paper under your eyelids to check the absorption level of moisture. You will need to close your eyes for about five minutes to allow tears to collect on the strip of paper. A weak result of the test can prompt your doctor to recommend special contacts that help maintain tears.

Trial and Prescription

After selecting the ideal pair of contacts, the optometrist may have you fit them before finalizing your prescription. They may need you to keep them on for around 15 minutes while monitoring your eye movements and tearing.

For more on contact lens exams, visit Smoot Eye Care at our office in Bedford, Indiana. You can also call (812) 675-4199 to book an appointment today.