It’s always a good idea to have an eye exam before getting any new prescription eyewear, and this includes contact lenses. If you want to wear contacts, the exam you’ll need is a little different to that for regular glasses. This is because of their position. Contact lenses are worn directly on the surface of the eyes rather than a centimeter or so in front. As a result, your eye doctor needs to take several things into account when helping you to decide which contact lenses are right for you. These include:

Your contact lens prescription. The position of the contacts on the surface of the eyes means that this will be different to a glass’s prescription.

The curvature of your cornea. This is the clear domed lens covering the front part of the eye. Everyone has a slightly different cornea, and the shape of the curve can influence the type of contact lenses that will both fit you properly and offer optimal vision.

Corneal irregularities. Some people suffer from corneal irregularities. These can range from scratches and other damage to an uneven surface or extensive bulging. Patients with corneal irregularities nearly always need a type of speciality contact lens.

Your tear film. Contact lenses float on the surface of the eye, which is usually covered in a thin layer of tear film. This tear film is made from a combination of oils, water and proteins and helps keep the eyes hydrated and comfortable, as well as supporting the lenses to move around in conjunction with the eyes when we look around. If you don’t have enough tear film, regular contact lenses may not fit properly or comfortably. Fortunately, speciality contact lenses can help to overcome this problem, with one type in particular – scleral lenses – creating a reservoir to trap tear film and keep the eyes hydrated.

 

How is a contact lens exam different from a conventional eye exam?

Your contact lens exam will include various elements that will provide your eye doctor with the information that they need to determine what size and type of contact lenses are best for you. These additional tests will include:

• Taking your corneal measurements to assess the curve of your cornea. This is usually done using an instrument called a keratometer, although computerized measurements may also be completed. This is known as corneal topography.
• Pupil and iris measurements. This helps your eye doctor to assess the size of your pupils and iris and select the right contact lenses for you.
• Tear film evaluation. This is often done using a tiny piece of paper inserted into the lower eyelid to measure how much tear film you produce.

Once your eye doctor has made a recommendation for the type of contact lenses that they feel would suit you best, you may be given a generic pair to try. You’ll be asked to put them in and remove them, and your eye doctor will assess how well they fit and how stable they are, before ordering them in your prescription. In some cases, it may be necessary to try several different types in order to find the right ones.

If you would like to schedule a contact lens exam, or if you have any questions about what to expect, call Positive Eye Ons Optometry in WEst Hollywood at 323-651-5646.