Contact lens Q&A with our optician

Our in house optician Benjamin Dumaine recently took part in a question and answer session with customers who wanted to know more about contact lenses and general eye care.

Some of the subjects discussed include:

• Caring for your contact lenses
• Your lifestyle and your lenses (sleeping in lenses, swimming with contacts etc)
• Eye dryness and lenses
• Your eyes and eyesight problems when using lenses
• Eye tests and lens prescriptions
• Coloured and tinted lenses

Contact Lens Care

• I'm an active, healthy nineteen year old girl who wears contacts. I like to wear my lenses day and night for up to a couple of months. I've been told by my optician that this could cause permanent damage to my eyes. Is this true?

  L.P Fodalming

• While I sympathise, your optician is absolutely right. You are most certainly risking permanent damage to your eyes. Wearing lenses for longer periods than recommended means that your eyes can't rest, and they can't get the vital oxygen they require to keep them healthy - even if your lenses are gas permeable. If you keep this up you risk infection, swelling and distortion of the cornea, and you have an increased risk of eye lid changes and allergies which can be irreversible in certain cases.

  So far, you've been incredibly fortunate. However, if you continue to wear lenses for longer periods than recommended, you will eventually have problems which could be severe. Your eyes are much too important to take unnecessary risks with!

• If contact lens solution is as safe as we're lead to believe, what is the problem with changing the type we use?

  D.M. Edinburgh

• Different types of contact lens solutions have specific properties which make them suitable for use with certain types of lens. Use the wrong solution with the wrong lens, and not only do you risk lens discolouration, you may cause an allergic reaction. Some of the preservatives used in solution manufacture can be harsh and a leading cause of problems with lenses is inadequate care or the wrong care. Take your optician's advice and use the cleaning solution that is correct for your lenses. While it's tempting to save a few pence, your eyes deserve the best care possible.

• My daughter suffers from short sightedness and wears spectacles. She now wants contact lenses and while I don't mind in theory, I don't think she is responsible enough to handle lenses and care for them correctly. Although I have stressed the dangers of wearing contact lenses that have been prescribed for others, I have caught her wearing her friend's lenses on two separate occasions. Is there any way I can get her to take the dangers of sharing contact lenses on board?

  S.B. Birmingham

• You're absolutely right! People should never wear other people's contact lenses. Apart from the damage that can be caused by badly fitting lenses, or contact lenses that are not the correct prescription, bacteria can be transferred from another person's eye.

  Perhaps show her the replies to some of our other questions, or arrange for her to see a contact lens practitioner or optometrist who can explain the dangers and show her photographs of some of the problems that lens sharing can result in.

• Can I sleep in my contact lenses?

  T.W. Leicester

• Certain types of lens, called 'extended wear lenses' have been designed so that you can sleep in them. However, they are not suitable for everyone and your optician will be able to advise you as to whether they are appropriate for your specific eye condition. You should not combine extended wear lenses with daily wear lenses as you could deprive your eyes of oxygen which may cause permanent damage to the cornea. If you still wish to wear contact lenses during sleep, speak to your optician who will be able to properly advise you of your options.

• I'm thinking of soft contact lenses. Advantages and disadvantages?

  B.D. Wigan

• Soft lenses are highly popular for several reasons. Firstly, they're comfortable. They also come in various formats and can correct vision to an excellent degree. There are soft lenses that can correct astigmatism, and even bifocal lenses. Disposable soft contacts are easy to use and relatively safe if you maintain good cleansing and storage routines.

  Though there aren't many negative points, soft contact lenses can alter slightly over time. They can absorb tears and also sometimes absorb debris and dirt from the air. This can cause the surface of the lens to partially disintegrate and reduce acuity of vision, and can occasionally result in a lack of oxygen flow to the cornea.

• Can my contact lens roll up, and become lodged behind my eyes?

  N.D. Cambridge

• No

• Some time ago I purchased some contact lenses but after about four months I stopped wearing them as I found that my eyes became irritated. I'm thinking of giving them another go but as it's around fifteen months since I last used them and though I've stored them in the correct solution I'd like to check whether they'll be okay. Or, will I need to get new contact lenses?

• After sitting for so long the solution is likely to be swimming with bacteria which will have coated the lenses and the lens material may be disintegrated or damaged. After such a prolonged period it is likely that your prescription will have altered in any case, and you should arrange a new eye test. Your optometrist may be able to shed some light on why your eyes felt irritated, and will be able to recommend a different type. In short, yes you definitely should get new lenses!

Your Lifestyle and your Lenses

• Can I wear my contact lenses when I'm sunbathing, or will the heat cause problems?

  I.M. London

• You shouldn't find that the heat causes problems. However, sometimes as the body gets hotter the cornea can swell slightly causing mild redness and irritation. Counteract this by using eye drops before sunbathing and wearing good quality, UV blocking sunglasses. This simple practice can also help in the prevention of future conditions including macular degeneration and cataracts.

• Can I wear my soft contact lenses for swimming or will they be affected by chlorine in the water?

  K.C. Dagenham

• Though you can swim in your soft contact lenses provided they are daily disposables it is advisable to also wear swimming goggles. The chlorine won't adversely affect dailies, but you should be aware of other potential hazards. Hot tubs, Jacuzzis and communal pools all attract a wide variety of nasty water borne bacteria. One in particular, acanthamoeba can be incredibly nasty and painful and in the worst case scenario can cause lasting eye damage.

  Water pressure may also present a possible threat as it can distort the lens and alter the fit. This is turn can distort the cornea, again leading to future eye problems.

  If you really can't see without contact lenses you may consider buying prescription goggles for swimming. Otherwise, take the safe option and remove your contact lenses before taking the plunge.

• I've worn my daily contacts in the past for scuba diving and it's been fine. Is it all right to keep doing this?

  B.D. Portsmouth

• Yes. You might also like to try putting in some eye drops before your dive and again when you finish. Occasionally, lenses may feel a little tighter due to different pressures, but on the whole contact lenses are perfect for SCUBA diving.

• I have a prescription for -5.75 in the right eye and -5.50 in the left. I would like to know what brand of soft contact lenses will give me the best protection from UVA and UVB rays. Which can you suggest?

  S-J K Chester

• I'd recommend the Acuvue brand of contact lenses ; they offer some of the best protection and all of their lenses have UV filter as standard. Try Acuvue Oasys or 1-Day Acuvue Trueye for the highest UV protection currently available. There are several other brands that use the same technology in good quality lenses, but to find the perfect lens for you it's always best to make an appointment for a fitting with your optometrist.

• I am 20 and have now been wearing my soft contact lenses for six years. My vision seems to be worsening. Furthermore, I've just discovered that blood vessels are growing towards my corneas as a result of wearing my lenses too much. My doctor gave me some eye drops and they made my eyes dry. Even when wearing glasses my sight seems worse than before and my eyes now look quite bloodshot. Can you tell me what could be causing this? P.S. I hate my glasses and once I have this problem fixed is there any possibility that I could have LASIK treatment? I really don't want to be stuck wearing glasses forever.

  V.L. Swindon

• From the details you've given me, it does appear that your eye problems may stem from over-wearing your contacts. Wearing contact lenses for extended periods can sometimes cause a lack of oxygen to the cornea. In turn, this can lead to corneal micro-trauma and can result in blood vessel growth on the cornea. If you haven't already contacted your optician, you should aim to see him as soon as possible.

  You may still be able to have LASIK treatment, even though you've experienced problems with your contact lenses. Much will depend on your eye health and how you care for your eyes, and you should discuss this with your optometrist. They can assess whether you will be suitable for LASIK treatment, and can give you information regarding potential risks and an overview of both positive and negative aspects of the procedure.

• I'm a 22 year old woman who has been wearing glasses for 10 years. I sometimes wear contact lenses and though my sight has been pretty stable for a long time, one eye has changed recently. Can I stop any further change and perhaps improve my vision?

  S.P. Rocheste

• This might just be a natural change. Sometimes contact lenses, gas permeable or soft, can alter the curvature of the cornea by a tiny amount which in turn will mean a change of prescription. Your optician will be able to recommend a course of action, if in fact any is required. Your eyesight might be stabilised over the next few years by updating your prescription.

• My optician recommends that I try Acuvue Oasys contact lenses. How will I know that they are fitted in the right place? Will they move if I blink?

  G.P. Thornton Heath

• All soft contact lenses have been specially designed to fit very well once you've put them in. Just insert them gently into your eye as instructed, blink once or twice and they should be perfect. Lenses should cover the iris, the coloured area of your eye, though in fact they sit on top of the cornea, which covers the iris.

  The most vital part of getting contact lenses is to have your eyes tested by a fully qualified optometrist. They will check that your eyes are healthy and that you're not likely to have problems, and ensure that your contact lenses fit correctly.

• Because blood vessels are growing on to my cornea, my practitioner has advised me to change to hard contact lenses. Are there any alternatives to hard lenses that would allow more oxygen on to my eyes?

  J.W. Manchester

• You've been given the right advice by your contact lens practitioner. Soft lenses would only encourage increased growth of blood vessels into the cornea, but gas permeable contact lenses will halt this.

  You could ask about the newer silicone hydrogel soft contact lenses which increase delivery of oxygen to the cornea if you're intent on soft lenses.

Eye Dryness and contact lenses

• I would very much like to keep wearing contact lenses but have been diagnosed with eye dryness. Would a contact lens with a lower water rate help?

  J.C. Bristol

• Lenses that have a lower water content may be of benefit to some patients who suffer from eye dryness. However, a growing number of practitioners prefer to prescribe lenses with a higher water content, and occasionally thicker lenses can be helpful.

• Why do some contact lenses feel drier than others? Is it better for me to choose a higher or lower water content when selecting lenses?

  D.R. Jedburgh

• Contact lenses are made from a wide range of materials, normally plastics and silicones, and all have specific characteristics. The environment leeches moisture from the surface of lenses during wear, and other factors such as health, whether you're taking medication, temperature and humidity, tear flow and even what type of cleaning system you use can have an effect on how they feel.

  Some opticians prefer to prescribe a contact with a higher water content for patienst who suffer from eye dryness, while others feel that a low water content is more beneficial. Some lenses are made from evaporation resistant material such as Coopervision Proclear which is manufactured by Bausch and Lomb, or Acuvue Optix and Air Optix Night & Day by CIBA Vision. PureVision from Bausch and Lomb and Acuvue Oasys by Johnson and Johnson are silicone hydrogel lenses which may also prove to be effective.

Your eyes and eyesight problems when using lenses

• My optometrist informed me that as a result of over-wearing my contact lenses, blood vessels had grown into the back of the iris. I was told that I couldn't be fitted with new contact lenses. What eye condition is this, and what can I do in future?

  K.T. Bridgend

• It seems likely that over-wearing your contact lenses has resulted in the cornea being starved of oxygen. This can stimulate blood vessel growth or 'neovascularisation' in areas where they wouldn't normally be present. If blood vessels continue to grow too far into the cornea they can cause real problems.

  When you stop wearing contact lenses this will stop the growth. However, it is often the case that although the blood inside the vessel vanishes, the blood vessel itself remains, meaning that you would no longer be able to wear contact lenses. It may be possible to choose a higher oxygen content permeable lens to enable you to resume wearing contact lenses.

• I've now been wearing soft contact lenses for about fifteen years. Unfortunately, I seem to constantly have red, bloodshot eyes and sometimes this can get really bad. I've tried wearing glasses for long periods instead, but I actually seem to be better when wearing contact lenses. What can I do, and might this be an indication of another, underlying condition?

  H.L Edinburgh

• I would advise you to book an appointment with your optician so that this can be investigated fully. The most probable cause is dry eye syndrome or some form of allergy. Wearing lenses when inflammation is present can cause it to become worse, so try to wait till the main cause has been determined before you wear contact lenses again.

• I had to stop wearing contact lenses because small bumps were discovered inside my eyelids. Prior to this there was some discharge. Can you tell me what may have caused it?

  M.B. Newcastle

• These symptoms often signify an allergic condition such as giant papillary conjunctivitis or GPC for short in contact lens wearers. It is caused by a build-up of protein on the contacts and can be exacerbated by a reaction to contact lens solution.

  The first step it to see your optician for a thorough eye examination. Once the condition has been diagnosed you should stop wearing contact lenses for a while and you might need to use anti-inflammatory eye drops.

• I was advised by my contact lens practitioner to change to a soft lens as my pupils were enlarged in the evenings and my vision was blurry. The problem is, that I find it difficult to read letters because the soft contact lenses, particularly the left, don't completely correct my astigmatism. Is there any solution?

  G.M. Devon

• Talk to your optician. There are some options; larger fitting gas permeable contact lenses sometimes help to reduce glare for those with large pupils. There are also soft lenses which can correct astigmatism.

• Can strabismus be corrected with contact lenses, or will they make it more noticeable? Also, is surgery an option when a child is older, and what are the alternatives to glasses?

  B.M. Hampstead

• Often referred to as a squint or 'cross-eyes', strabismus can usually be treated with contact lenses. Sometimes, only one eye is affected, and in young children an eye patch is often used to correct the 'lazy' eye by making it work harder. Contact lenses can be used in much the same way.

  You could ask to be referred to an Orthoptist, who will give your child eye exercises to help reduce squinting. Combined with other steps, it may completely correct the condition. If the squint remains when your child is older corrective surgery may be an option. Consult a specialist for more informed, in depth advice.

• Twelve years ago I had a corneal ulcer. At the time I wore contact lenses. Are there any modern lenses that I could wear now?

  M.P. Ayr

• Many people who have had previous corneal problems can wear contact lenses now. However, this will depend on your personal circumstances and the best person to offer guidance is your optician.

• I've worn contact lenses every day for about 10 years. Now, when I go back to glasses I find that my eyes water far more than they previously did. I'm also more light sensitive. Is it possible that I've worn my lenses too much? The contact lenses I have now are -2.50D and they're 6 months old.

  C.J. Rhyl

• I hear this problem fairly often and you might have simply become used to wearing contact lenses. Perhaps you didn't have your glasses prescription updated? You may be seeing things a little better with contacts and the difference is more noticeable, and the increased distance between your eye and the lens may allow more air in making your eyes more prone to water. Wear your glasses for several days and your eyes may settle.

• I had a conjunctival haemorrhage 3 days ago? How long before I can wear my contact lenses again?

  G.F. Scarborough

• See your optician, they will be able to advise you when to start wearing your lenses. Don't be tempted to pop them in before seeking advice, it could damage your eyes if your wear them too soon.

Eye tests and lens prescriptions

• Is a prescription for glasses always higher than one for contact lenses? If yes, does it matter whether the contact lenses are soft or gas permeable?

  W.D. Aberdeen

• The distance between the front surface of the eye and the back surface of the lens is known as the vertex distance. Because a contact lens sits directly on the eye surface the vertex distance is much less. This means that less lens strength is needed to focus light on to the retina. The same is true whatever type of lens you choose.

Coloured and tinted lenses

• I have recently been told that it is possible to have a surgical procedure to change the colour of the eye. At present I wear various coloured contact, but because I have astigmatism and have problems with my sight I wondered whether surgery might be a solution.

  B.K. Poole

• No. Your eye colour is determined by the pigment present in the iris. The iris is one of the most important parts of the eye, and if by any stretch of the imagination this were possible, it would be a delicate operation that would carry great risk. At present surgery cannot change your eye colour.

  However, there are some excellent contact lenses which enable you to experiment with different eye colours to your heart's content.

  As yet, there is no surgery to change eye colour. Why settle for one colour when you can try a different shade to match every outfit. Astigmatism can also be corrected by contact lenses in most cases, depending on your prescription.

• Can I change my eye colour or accentuate the natural colour using contact lenses? My natural eye colour is predominantly green with a ring of brown around the pupil. I'd like to enhance the green and perhaps cover the brown but I don't really want to rely on coloured contact lenses. Can you help?

  L.V. Dundee

• To be honest, no. The best solution currently available is coloured contact lenses. They can change the colour and appearance of your eyes easily and safely, so why not give them a go?