There are many different types of contact lenses used by people in a whole range of situations. However, the one thing that they all have in common is following the correct cleaning and hygiene measures, which are vital in avoiding any serious problems with lens wear. The two main problems that can be caused by poor cleaning and hygiene with contact lens wear are: the risk of an eye infection a poor level of oxygen reaching the front of the eye. Why is this important? Infections of the eye can range from mild, which makes the eye slightly red and uncomfortable, to a serious ulcer, which is painful and can cause a serious risk to the vision in the eye. Again, if the eye doesn’t get enough oxygen through the lens to remain healthy, the eye can suffer from changes that can make vision blurred and cause long-term damage to the cornea. The overall risk of these complications is low, provided the cleaning and care instructions are well followed. This article aims to highlight the important points of good contact lens care.The best routine for caring for your contact lenses may depend on the type of contact lenses you use. This may be in terms of the material used – whether it’s a hard lens like a rigid gas permeable lens or a soft lens. It may also depend on whether your lens is a daily disposable lens or a lens that is designed to last for a set period of time, eg a fortnightly lens or a monthly lens. Daily disposable lenses don\'t require any daily cleaning because they are thrown away after one day\'s wear. It\'s important that these lenses are never reused. Because the wearer is always using a new lens, these are safe in terms of reducing the risk of an infection and can be used in patients who have had problems with other lens types. However some of the advice below on hygiene measures still applies to these lenses. If you wear contact lenses that are designed to last for a fixed period of time, they will require daily cleaning as instructed by your optometrist in order to reduce the risk of problems. Whether you wear a hard lens or a soft lens, you\'ll be advised on a suitable contact lens solution that will be used to ‘clean’ the lens after a day’s wear, followed by overnight \'soaking\' in a clean case. The solutions may consist of either a \'multi-purpose\' solution in one bottle or a two bottle system – one for cleaning and one for soaking. These solutions will be specific to either hard lenses or soft lenses. In general, all lenses need to be cleaned after they have been worn for a day. This involves placing the lens in the palm of the hand, covering it with the cleaning solution and giving it a gentle rub with the tip of your finger for about 30 seconds. This cleans the surface of the lens of any deposits. The lens should then be placed in the case in fresh soaking solution overnight. The lens is then ready to be used in the morning without any further cleaning. It may be useful to have \'saline\' at hand when cleaning and handling the lens in order to rinse the cleaning solution. It\'s important that fresh solution is used each night. Also if the lens has not been used for a few days, it\'s important to go through the cleaning routine the night before wearing the lens again. With all solutions, always read the enclosed instructions on their proper use, and discard bottles when they exceed their expiry date.Some people can have an allergic reaction to their lens solutions due to one of the ingredients. If the eyes become red, watery and feel burning or itchy, it\'s possible that this is what has happened. In this case, take the lenses out, and consult your optometrist. There are other solutions available that don’t contain any preservatives, which your optometrist can instruct you on. These prevent most allergic reactions. It may also be suitable to change to a daily disposable lens, which would remove the need for cleaning solutions.The following rules of contact lens wear apply to all types of lenses, regardless of type and material. Handwashing: always wash and rinse your hands thoroughly with an antibacterial soap before any handling or cleaning of the lenses. Domestic water: do not use tap water to clean or rinse the lenses. Tap water contains small bugs and bacteria that can cause serious infections and ulcers of the eye. This applies also to showers and swimming pools – contact lenses should not be worn in either of these situations. Contact lens cases must be cleaned and replaced regularly. A dirty contact lens case is one of the most common sources of serious eye infections. The case should be cleaned at least once a week, either with the solutions or with boiling water, and allowed to air-dry. Sleeping in lenses: unless your lens is designed to be slept in and has been arranged under the guidance of your optometrist, do not sleep in your contact lenses. This greatly increases the risk of an infection of the eye and other problems caused by a poor level of oxygen reaching the eye. Attend regular contact lens check-ups with your optometrist. The frequency of check-up will be decided by your optometrist. This is typically either once every six months or annually. This allows your optometrist to check for any signs of dryness, infection or long-term problems caused by poor oxygen levels. Adherence to their advice will greatly reduce the risk of any problems. If you buy your lenses online, it is also important to attend your optometrist check-up because there can be subtle long-term changes occurring that you as the patient would be otherwise unaware of.If you experience any problems, such as redness, discomfort or pain, discharge or reduced vision with your lenses, follow the steps below. Remove the lenses and retain them along with their case for your optometrist to examine. Do not reinsert your lenses until you have consulted your optometrist or an eye doctor. Phone your optometrist and report your symptoms. They will arrange to see you as urgently as required. If it is outside normal office hours and you have a major concern in terms of pain or reduced vision, contact your GP surgery or NHS Direct or NHS 24 (Scotland) for further advice.