Contact Lenses are great Alternative to wearing Eyeglasses
The Importance of a Comprehensive Eye Exam
Whether you have vision problems or not, having your eyes checked regularly ensures proper eye health, with no developing eye conditions. A comprehensive eye exam checks both the general health of your eyes and your visual acuity. During this exam the eye doctor will decide your prescription for eyeglasses. This prescription alone is not enough for contact lenses. The doctor will check for any eye health issues, such as dry eye, that could interfere with the comfort and success of contact lens wear.
Contact Lens Fitting
Contact lenses are not a one size fits all item. To fit your lenses properly, the optometrist will need to measure your eye. Improperly fitting contact lenses could cause discomfort, blurry vision or even damage the eye. The measurements your eye doctor will take for a contact lens fitting include:
To ensure that the curve of the lens properly fits to the curve of your eye, your doctor will measure the curvature of the cornea (the front surface of the eye). The curvature is measured with a keratometer which determines the proper curve for your contact lenses. If you have astigmatism, the curvature of your cornea is not perfectly round. A “toric” lens, which is designed specifically for an eye with astigmatism, would be used to offer optimal fit and comfort. In certain cases, your eye doctor may decide to measure your cornea in greater detail with a mapping of the corneal surface called corneal topography.
Your eye doctor may measure the size of your pupil or your iris (the colored area of your eye) with an instrument called a biomicroscope or slit lamp or manually with a ruler or card. This measurement is important if you are considering specialized lenses such as Gas Permeable (GP) contacts.
One of the most common problems affecting contact lens wear is dry eyes. Contact lenses that are not kept properly hydrated become dry causing the eyes to become itchy and irritated. If you have dry eye syndrome, your doctor will want to make sure that you have enough tear film to keep the lenses moist and comfortable. If not, contact lenses may not be a good vision choice.
A tear film evaluation is performed by the doctor by putting a drop of liquid dye on your eye and then viewing your tears with a slit lamp. Another way is by placing a special strip of paper under the lid to absorb the tears, seeing how much moisture is produced. If the tear film is weak, your eye doctor may recommend certain types of contact lenses that are more successful in maintaining moisture.
You may be asked to try on a pair of contact lenses to feel if the fit is comfortable. The doctor, or assistant, will insert the lens. You will keep them in for 15-20 minutes before the doctor exams the fit, movement and tearing in your eye. If, after the fitting, the lenses appear to be a good fit, these contact lenses will be ordered for you. Your eye doctor will also offer care and hygiene instructions including: how to insert and remove your lenses, how long to wear them, and how to store them, if relevant.
To assure that your eyes are adjusting properly and your contacts fit well, you may be requested for a follow up appointment. Visit your eye doctor if you experience any dryness or discomfort while wearing your contact lenses. Your eye doctor may decide to try a different lens, a different contact lens disinfecting solution or to try adjusting your wearing schedule.