There are a number of factors which determine the suitability of sleeping in lenses. Firstly, the lens must provide high oxygen transmissibility. Since the eyes are closed during sleep air is unable to reach the cornea which is reduced further when a contact lens is worn.
Oxygen deprivation can cause detrimental long-term effects such as corneal scarring. Only silicone hydrogel lens materials provide high enough oxygen transmissibility to be safely slept in.
The second consideration with extended wear is the risk of infection. Sleeping in contact lenses increases the risk of developing an eye infection. Children, people with a history of eye infections or who have compromised immune systems are recommended not to sleep in lenses.
- If eye redness or eye pain occurs when wearing your contact lenses, remove the lenses immediately. If the redness and pain persists on removal, see your Optometrist immediately.
- Only wear your contact lenses for the prescribed time. E.g. monthly lenses should be changed every month- we recommend marking the day on your calendar, or ensuring that you change your lenses on the same day of every month e.g. 1st of every month.
- Do not sleep in lenses unless they have been prescribed for that purpose.
- Ensure that you are cleaning your contact lenses properly and with the correct solution.
- Ensure that every time you open a fresh bottle of solution, you also replace your contact lens case. Old cases are breeding grounds for bacteria!
- Do not wear your contact lenses when you are sick or in hospital.
- For daily disposable CL wearers, do not sleep or nap in your CL.
- Wash your hands before handling your lenses.
- Do not wear lenses in environments where contamination is likely ie. swimming in rivers.
Whether a contact lens is monthly, fortnightly or daily largely depends on the breathability/oxygen transmissibility of the lens. Certain materials such as silicone hydrogels, which are used in fortnightly and monthly contact lenses have high oxygen transmissibility and are tougher and more resilient for longer term wear.
As a result, they are thicker, and as such, sometimes pose a comfort issue for patients. Daily lenses, tend to be made from a hydrogel material which is more comfortable, however less breathable. As a consequence, over wearing these contact lenses puts the wearer at a higher risk of developing complications and eye infections.
Yes. Over wearing contact lenses increase the risk of eye infections. Most eye infections are mild and treatable yet severe infections have the potential to permanently affect vision and in some cases may lead to blindness.
The people most susceptible to eye infections are those who sleep in their lenses especially when they’re sick, people who wear lenses beyond the recommended schedule ie. A monthly disposable lens being worn for 6 weeks, and people who don’t clean their lenses. Over-wearing lenses increases the number of micro-organisms which attach to the contact lens surface and can therefore interact with the eye.
To decrease the bacterial load on a lens it is imperative that you wash your hands thoroughly with anti-bacterial hand wash, clean the lenses every day and avoid wearing the lenses in certain environments such as swimming in rivers and spas.
If your eyes become red or sore whilst wearing lenses, remove the lenses immediately. If the irritation subsides after the lens has been removed then inspect the lens to make sure it hasn’t been inserted inside out or has a rip or tear. If necessary insert a new lens.
If the irritation returns after re-insertion or does not subside after removing the lenses contact your Optometrist immediately. An Optometrist is able to determine by using a slit lamp biomicroscope whether you have an eye infection and can recommend the appropriate treatment.
It is best to consult an Optometrist rather than your General Physician since most General Physician do not have access to slit lamp biomicroscopes. The quicker an infection is diagnosed and treated the faster the recovery and the less likely of permanent visual impairment.