Hard to Fit Contacts
Human eyes come in many shapes and sizes, like our bodies, so fitting contact lenses is akin to tailoring an outfit. However, most patients receive properly fitting lenses by following the appropriate contact lens fitting steps. If you live in the Tucson area and are looking for an eye doctor near you, contact our team at Advanced Vision Care.
Why Contact Lenses Can Be Hard To Fit
The correct contact lenses depend on the overall shape and curvature of the eyes, the size of the cornea, pupil, and iris, the material used for the contact lens, and the wearer’s lifestyle. The combination of these factors makes the fitting process complex, despite the high-tech tools we use to measure the eyes.
Achieving the proper fit is a matching process in which your eye doctor considers various physical measurements of your eyes, your eyes’ ability to produce the quality and quantity of tears, and the patient’s age and lifestyle. These factors can determine the choice of lens material, whether to try daily or extended-wear contacts, and their replacement schedule.
The Contact Lens Exam and Fitting Process
Fitting your contact lenses ensures that they rest comfortably on your cornea. The fitting is an eye exam during which your optometrist takes precise measurements of your eyes. The typical tests include the measurements below.
- Cornea Shape and Curvature: A keratometer, or the more precise corneal topographer, measures the shape of your eye based on how light bounces off your corneas. The tests identify the presence of an astigmatism as well.
- Pupil or Iris Size: Using a ruler or an automated process, they measure the size of your pupil or iris to identify the size of contact lenses you need.
- Tear Film: Placing a strip of paper under your lower eyelid allows your eye doctor to determine whether you have dry eyes and, if so, the severity. The measurement may indicate you are not a candidate for contact lenses or should wear a particular lens type.
The test results help determine the contact lenses for your trial fittings. Several trial contacts are worn for a few minutes to assess their comfort. Patients then receive a pair of trial lenses to wear for one week to confirm a proper match. If all goes well after one week, you can order a set of prescription contact lenses. Typically, you will return for a check-up to confirm they fit your eyes and lifestyle.