WHAT TO EXPECT
- Determine patient prescription through vision refractive error and cover tests
- Slit-lamp examination to determine the interior health of your eye
- Eye pressure test
- Pupil dilation, revealing the functioning of your retina (back of your eye)
A contact lens fitting involves both a consultation and measurement.
Your eye doctor will ask you about your lifestyle and preferences. Some contact lenses may be better for athletes with active lifestyles, for instance; others may be better for frequent travelers who might need to occasionally sleep in their contacts. Your eye doctor will also ask you about whether you prefer colored contact lenses or disposable contacts.
Your eye doctor will also need to gather several measurements. The following steps may happen in any order:
i) Corneal Measurement
- An instrument known as a keratometer determines the curvature of your cornea (clear part of your eye).
- Corneal topographer may be used to analyze how your eye reflects light, giving a precise measurement of your cornea.
- A wavefront eye exam may also be used to reveal if your have a astigmatism. Astigmatism is common – referring to any irregularities in the curvature of the cornea or lens. This is treated using gas permeable or toric contact lenses.
ii) Pupil and Iris Measurement
- The doctor will either use the ruler approach or a special machine to measure the horizontal and vertical diameter of your pupil and iris. This will ensure your contact lenses will appear natural to the size and color of the eye.
iii) Tear Film Evaluation
Dry eye syndrome is common among contact wearers. When your eye is not producing enough moisture they become red and irritated. This dryness will damage your eye which can lead to infection and inflammation.
Using a strip of paper and placing it underneath your lower eyelid will test your body’s ability to produce tears. This determines your tear production ability and in turn, will reveal the type of contact lens most beneficial to you.
If you suffer from dry eyes, a soft disposable lens with moisture technology may be recommended.
Schedule a follow-up appointment
Usually an initial contact lens fitting requires follow-up visits to make sure the lenses are resting properly on your eyes.
- Your contact lenses may fit well, allowing for sharper vision without experiencing discomfort.
- It may also take 1-3 follow-up appointments to find the perfect contact lens for you.
When the doctor confirms the contact lenses are continuing to fit well and that you are seeing clearly, comfortably and safely with them, your eye doctor will then finalize and sign a contact lens prescription.
Your prescription for contact lenses will include a number of designations that are not found on an eyeglass prescription, including:
- The brand of the contact lenses
- The curvature of the optical zone of the lenses (called the base curve, or BC)
- The diameter of the lenses
- An expiration date for purchasing replacement lenses
Your eye doctor might also specify wearing instructions on your contact lens prescription, such as, “Not to be worn overnight; replace every two weeks.”
Contact Lenses: all you need to know
Can lenses get lost behind the eyes or merge with them?
These are two really strong myths we hear about all the time. It is physically impossible to lose a contact lens behind one’s eyes because a membrane connects the eyeball with the eyelids, preventing the lenses from sliding behind the eye. Neither can they merge with the eyes since they are made of quality materials that are designed to stay on the surface of the eye. Using the recommended method, the lenses can be removed very easily.
Can contact lenses scratch the eyes?
Problems of this kind are rather rare. The vast majority of scratch problems are related to a bad adjustment of the lenses. Failure to follow the optometrist’s recommendations, such as how often to change lenses, can also damage your eyes. If you experience discomfort while wearing your contact lenses, remove them as soon as possible and consult your optometrist.
Can lenses fall easily?
With a good fitting done by the optometrist, your lenses will stay in place. If a lens moves, it will usually stay in the eye until it returns to its usual place.
Why do I need a prescription to get contact lenses?
Since contact lenses are visual orthotics, only an optometrist can tell you if there is a contraindication for you to wear contact lenses. By examining you with specialized equipment, your eye care professional will make sure that you can wear contact lenses safely. The optometrist or optician will then help you determine the type of lenses that will suit you according to your lifestyle, the shape of your eyes and your prescription.
Will my contact lens prescription be different from my eyeglass prescription?
Yes, the adjustment method is different for glasses and contact lenses. In order to adjust well the contact lenses, it is necessary to know the measurements of the eye, which will determine the diameter and the curvature of the lenses. In addition, because the distance between the eye and the lenses of your glasses is different from the distance between your eye and your contact lens, the prescription may vary. It is therefore essential to have a contact lens fitting before buying them, especially if you are presbyopic or astigmatic.
At what age can my child wear contact lenses?
There is no ideal age to start wearing contact lenses. Many children begin to wear them as teenagers, and even as pre-teens. As a parent, you are in the best position to determine if your child is mature enough to take good care of their lenses. Whether for aesthetic reasons or for sport, there are many reasons your child may want to wear contact lenses. Your optometrist and optician will be able to help you choose the types of contact lenses that suits them best.
Can I still wear glasses if I get lenses?
We recommend that you give your eyes a little contact lenses break by wearing your glasses alternately with your lenses. For example, many people remove their lenses when returning from work or school, or rest their eyes during the weekend by wearing their glasses. It is also possible to buy contact lenses for occasional use, such as for sport or special events. Moreover, contact lenses are ideal for sports because they provide better peripheral vision, do not fog up and avoid the damaging your glasses while doing sports.
Made of a firm polymer plastic material. They are easier to keep clean because they are less likely to absorb foreign material from the eye or environment. You must remove hard lenses before you go to sleep because they restrict the flow of oxygen to the cornea, which needs oxygen to stay healthy.
Made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.
Rigid Gas Permeable (RGP)
More durable and resistant to deposit buildup, and generally give a clearer, crisper vision. They tend to be less expensive over the life of the lens since they last longer than soft contact lenses. They are easier to handle and less likely to tear. However, they are not as comfortable initially as soft contacts and it may take a few weeks to get used to wearing RGPs, compared to several days for soft contacts.
Extended wear contact lenses are available for overnight or continuous wear ranging from 1 to 6 nights or up to 30 days. These are usually soft contact lenses made of flexible plastics that allow oxygen to pass through to the cornea. There are also very few rigid gas permeable lenses that are designed and approved for overnight wear. Length of continuous wear depends on lens type and your eye care professional’s evaluation of your tolerance for overnight wear. It’s important for the eyes to have a rest without lenses for at least one night following each scheduled removal.
Disposable (Replacement Schedule)
The majority of soft contact lens wearers are prescribed some type of frequent replacement schedule. “Disposable” means used once and discarded. With a true daily wear disposable schedule, a brand new pair of lenses is used each day.
Some soft contact lenses are referred to as “disposable” by contact lens sellers, but actually, they are for frequent/planned replacement. With extended wear lenses, the lenses may be worn continuously for the prescribed wearing period (for example, 7 days to 30 days) and then thrown away. When you remove your lenses, make sure to clean and disinfect them properly before reinserting.
Orthokeratology, or Ortho-K, is a lens fitting procedure that uses specially designed rigid gas permeable (RGP) contact lenses to change the curvature of the cornea to temporarily improve the eye’s ability to focus on objects. This procedure is primarily used for the correction of myopia (nearsightedness).
Overnight Ortho-K lenses are the most common type of Ortho-K. There are some Ortho-K lenses that are prescribed only for daytime wear. Overnight Ortho-K lenses are commonly prescribed to be worn while sleeping for at least eight hours each night. They are removed upon awakening and not worn during the day. Some people can go all day without their glasses or contact lenses. Others will find that their vision correction will wear off during the day.
The vision correction effect is temporary. If Ortho-K is discontinued, the corneas will return to their original curvature and the eye to its original amount of nearsightedness. Ortho-K lenses must continue to be worn every night or on some other prescribed maintenance schedule in order to maintain the treatment effect. Your eye care professional will determine the best maintenance schedule for you.
Our doctors are eye care professionals with decades of experience using overnight Ortho-K lenses in our practice.
Here are some dos and don’ts for cleaning your contact lenses:
- Do wash your hands with soap and water before touching your contact lenses.
- Use antibacterial soap where possible, and dry your hands with a lint-free towel. Don’t use oil or lotion-based soaps, which can cloud or soil your lenses.
- Do use fresh, contact lens cleaning solution every time.
- Don’t use tap or sterile water, saliva, saline solution or rewetting drops. None of these serve to disinfect and properly clean your contact lenses.
- Do rub your contact lenses with your fingers, and rinse them with fresh cleaning solution afterward.
“Rub and rinse” is the best way of cleaning contact lenses, even with “no-rub” contact lens cleaning solutions.
- Don’t let fingernails touch your lenses. Nails aren’t only sharp; they’re a great haven for germs and dirt.
- Do rinse your contact lens case with fresh solution, and leave it overturned and open to dry.
- Don’t clean your case with water, which can contain impurities and microorganisms. Also, don’t leave your case near the toilet or in humid places, which allow mildew and germs to build up.
Other ways to keep contacts clean
- Don’t transfer contact lens cleaning solutions into smaller containers for travel or storage, which can compromise the sterility of your solution.
- Keep your solution bottle tightly capped, and avoid contact with surfaces or objects while in use.
- Replace your contact lens case at least every three months.
- Never wear your contact lenses more than 30 days after first opening.
- Avoid air smoke and other pollutants, which can enter your eyes and cause irritation and infection.
- Always follow instructions
Instructions that accompany your contact lenses, your contact lens case and your contact lens cleaning solution are, along with your eye doctor’s directions, designed to provide the best care and performance for your particular wearing and cleaning context.