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Frequently Asked Questions

This page has a list of contact lens questions. Alternatively you can see FAQs on:

General Issues
The Eye Examination

I want contact lenses. Why do I need a different examination?

Although contact lenses are very liberating, and much more advanced now than they were even 5 years ago, they are still a foreign body in the eye and have the potential to cause harm if not fitted correctly. A contact lens fitting covers a lot of aspects that are not relevant to a normal eye examination.

We will discuss exactly what you want lenses for, what you expect from them and how often you intend to wear them We examine the front of the eye in much more detail for contact lenses than we do for spectacles.

We measure the shape of your eye to help decide which lenses will be most suitable and to make sure that lenses fit correctly

We check for scars or flaws in the cornea, conjunctive and eyelids that could be aggravated by lenses

We examine your tears to make sure that they will not be affected by the lenses and that they will cushion and moisturise the lenses properly

We try different lenses to determine the best lens for you and we check how these lenses are affecting your eye to make sure that they are unlikely to cause you any harm

We teach you how to insert and remove lenses and how to look after them

Contact lenses are not the same as spectacle lenses. If you have a strong prescription or astigmatism your contact lens specification could look completely different to your spectacle prescription.

Why can’t I just buy lenses off the internet?

You could, BUT…………

Contact lenses are a foreign body in the eye and have the potential to cause great harm if not fitted correctly.

A contact lens specification is not the same as a spectacle prescription and not all contact lenses are suitable for all people. You need a full fitting before you can safely have lenses. The internet supplier may not provide any information on the correct cleaning solution for the lenses and will not teach you how to handle the lenses safely.

If you wear contact lenses and do not have regular aftercare appointments you risk permanent damage to your eyes. Early contact lens related problems do not always cause symptoms. Your eye care practitioner is trained to spot the early signs of problems and to deal with them before they cause damage or vision problems.

Once you have had a contact lens fitting you will be issued with a contact lens specification. You can use this to order lenses off the internet but remember that you will still have to pay for regular aftercare appointments with a qualified optometrist or contact lens practitioner. Make sure that your price comparison includes the cost of eye care and solution as well as lenses.

All internet suppliers are required by law to ensure that you have an up to date contact lens specification. If they do not ask you to provide this then they are breaking UK law and should not be considered to be a reputable company. They may also be supplying fake lenses which will not have been subjected to the same rigorous quality and safety tests as the genuine ones.

Not all contact lenses are the same, even if the numbers look the same. You will have been fitted with a lens specific to your requirements and a company offering substitute lenses cannot possibly know what will suit your eyes.

Watch out for expensive delivery charges and offers that look fantastic until you realise that you have to buy in bulk to get the advertised price.

Caveat Emptor!

Can I wear my contact lenses in the swimming pool?

Swimming in lenses is not recommended either in the pool or in the sea.

Gas Permeable lenses can wash out and soft lenses will absorb water and all its associated bacteria.

If you are playing in a pool rather than serious swimming and really feel that you must wear lenses we would recommend that you wear daily disposable lenses and remove them within an hour of leaving the pool. This reduces the risk of infection as any harmful organisms that may have been absorbed into the lens do not have time to multiply or react with the eye.

If you are a serious swimmer then prescription swimming goggles are a safer option and are readily available.

Can I sleep in my contact lenses?

That depends on the type of lens that you have been prescribed.

Daily disposable, standard monthly disposable and annual replacement soft contact lenses are not licensed for overnight wear and can cause damage to the eyes as they do not allow enough oxygen to the cornea.

If you want to be able to sleep in your lenses you need to be fitted with Silicone Hydrogel Lenses licensed for extended or continuous wear.

Some Gas Permeable lenses are suitable for over night wear. Discuss this with your optometrist or contact lens practitioner.

Why can’t I use a cheaper contact lens solution from the supermarket?

Not all contact lens solutions are suitable for use with all lenses. You will have been prescribed the most suitable lens and solution combination for your eyes. Changing your solution without consulting your eye care practitioner is not recommended as the outcome cannot be predicted.

If you can buy your usual solution in the supermarket at a lower price then you can obviously do so. However, if your lenses come with solution as part of a monthly package you may find that you pay more in the supermarket.

Why shouldn’t I use my friend’s coloured contact lenses?

Coloured contact lenses carry the same risks as prescription lenses. They are made of the same materials and need to be fitted properly in the same way that prescription lenses do.

You may not be suitable for contact lens wear and they could damage your eyes.

Contact lenses absorb contaminants from the tears. If you use someone else’s lenses you risk eye infections, or worse. HIV has been found in tears and could theoretically be transferred on a contact lens.

My eyes are red, is it safe to put my lenses in?


You should never put a contact lens into a red eye.

If your eyes are red there is a reason for it, and sticking a foreign body in there could aggravate the situation and lead to permanent damage.

If you have a red eye you should consult your eye care practitioner as soon as possible.

If you are on EyeplanTM this emergency appointment will be free