Eye Health Central

Contact lens fitting: getting the right lenses

Contact lens fitting: ensure comfort and improve your vision

For those who wish to wear contacts, it's important to remember that the standard prescription provided by eye care practitioners is generally only for eyeglasses. There are additional measurements that must be taken in order to get the right lenses for your needs.

Every eye is different - your left is slightly different from your right, and your eyes are different from those of everyone else around you. Differences include the diameter and the curvature of your eye, not to mention the severity of any vision problems that you might have. This is why getting a precise contact lens fitting is so important.

If you have problems with your vision and want to use contacts to correct the problem, or if you wish to get coloured contacts for cosmetic purposes, a contact lens fitting is something to consider before you start shopping.

What Happens During a Contact Lens Fitting?


Most appointments will begin with the eye care professional determining the overall health of your eye. Your corneas will be examined, using a instrument called a slit lamp, to ensure that they are healthy enough for wearing contact lenses. Your eye care specialist will also make a note of the condition of your eyes to refer back to on future visits to ensure that your ocular health hasn't deteriorated due to wearing lenses.

The next step will be to take careful measurements of your eye using a special instrument called a keratometer. Your eyes may also be scanned by a computer to map the curvature of the surface of your eye and to provide more detailed analysis. These dimensions will determine the shape and size of your lenses.

In addition, a contact lens fitting could also include a test to evaluate the tear film on your eyes. The specialist may also ask if you any allergies, hay fever or dry eyes and enquire about your lifestyle. All of this information will help the eye care professional determine how prone your eyes are to dryness, and help to ensure that you choose a contact lens type that suits your needs. 

The Optometrist will also inquire as to why you want contact lenses - are they for occasional use/full time use/ for sport or some other specific activity. Do you want the convenience of daily lenses or would you prefer to clean and store monthly lenses every night? Do you want to sleep in your contact lenses for 30 days at a time using continuous wear lenses? Would you like to change your eye colour with coloured prescription lenses. If you are over 45, he/she may recommend multifocal contact lenses to help you with reading.

What is a 'Contact Lens Trial'?

The Optometrist will have gathered enough information by this stage to recommend a particular type of contact lens to you - one that satisfies all of yours (and their) criteria to achieve the best chances of success.

Normally the Optometrist will have 'fitting sets' available in the practice , which are sets of contact lenses provided to him by the main contact lens manufacturers, from which he will choose the brand and power that he/she wants to try.

The Optometrist will insert the contact lenses into your eyes - don't worry this is a simple procedure and he/she will have done this many times before. After a check to ensure you are comfortable and can see well enough, you will be asked to either wait outside the consulting room or walk around for 20-30 minutes to let the contact lenses settle down in your eyes.

On returning the optometrist will ask you how the trial has gone , from your perspective. Any discomfort? How is your vision? 

They will  then check your vision wearing the contact lenses and he will perform something called an 'over refraction'. Here e/she will work out how much extra power you need in your lenses to see clearly. He will also check the fit of the contact lenses using a instrument called a slit lamp. Basically a large horizontally mounted low power microscope.

Finally he will remove the contact lenses and will  probably put a non stinging dye into your eyes and once again check your corneas using Ultra Violet light to make sure there are no scratches or other anomalies.

If all is normal, the Optometrist will normally order your contact lenses in, if he does not have your power or fitting in stock, and arrange for a 'Handling session'

Inserting soft lensesWhat is the 'Handling Session'?

You will be taught, usually by a staff member who is trained in this area, how to handle your contact lenses. Specifically you will be taught:

  • How to insert and remove your contact lenses
  • How to care for and clean your contact lenses
  • Basic hand hygiene techniques
  • Tips and advice, like how to tell if your contact lens is 'inside out'
  • Given a wearing schedule i.e 4 hours on the first day and increase by 2 hours per day to a maximum of 14 hours.

Finally, you will be scheduled for an 'aftercare' appointment, usually after two weeks. On this appointment you will get a chance to  ask the Optometrist any questions that you have about your contact lenses. They will recheck the fitting and vision and generally make sure that everything is normal. At this stage the Optometrist may make slight adjustments to the power and issue a final Contact Lens Prescription.

After the Fitting - You can Choose Where to Buy your Contact Lenses

Once you've had a proper contact lens fitting and been taught how to handle them, you can choose to get your contacts from any source - not just your optician. Be sure to ask for a copy of your Contact lens Prescription - it is a requirement in law to give you a copy, and will clearly identify the Brand/Fitting and power of your contact lenses.

Here on our website we offer a wide range of lenses from leading brands and at affordable prices.

Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 24 Apr 2015, Last modified: 4 Mar 2020