What happens if you wear contact lenses for too long?

Wearing your contact lenses for too long deprives your eyes of oxygen, which can lead to redness, discomfort, blurry vision, and a higher risk of infection. Most soft lenses are safe to wear for 8 to 12 hours a day. If your eyes feel sore or irritated, remove your lenses straight away and give your eyes time to rest.

Whether you’ve dozed off on the sofa still in your lenses or just lost track of time during a long day, it happens to most contact lens wearers at some point. But how bad is it really, and what should you do? Here’s everything you need to know. 

What happens to your eyes when you wear lenses too long? 

Your eyes need a steady supply of oxygen to stay healthy, and they get most of it directly from the air rather than from your bloodstream. Contact lenses sit on your cornea, and when you wear them for longer than recommended, they reduce the amount of oxygen reaching your eye. Over time, this can cause a range of problems. 

The main issues associated with overwearing contact lenses include: 

1. Hypoxia (oxygen deprivation), where the cornea becomes starved of oxygen and starts to swell. 
2. Deposit build-up on the lens surface, which can irritate the eye and reduce visual clarity. 
3. A significantly increased risk of eye infections, including serious bacterial infections such as microbial keratitis. 
4. Corneal neovascularisation, a condition in which new blood vessels grow into the cornea to compensate for the lack of oxygen. This is a sign of long-term overwearing and should be assessed by an optician. 
5. Increased dryness and discomfort, as the lens draws moisture away from the eye surface over time. 

Symptoms of overwearing contact lenses 

Your eyes are usually pretty good at telling you when something isn’t right. If you’ve been wearing your lenses too long, you may notice: 

6. Red or bloodshot eyes 
7. Eye pain or soreness 
8. Blurry or hazy vision 
9. Dryness and irritation 
10. Sensitivity to light 
11. A sensation of something stuck in your eye 
12. Excessive watering or discharge 

These symptoms can range from mild discomfort to something that needs prompt attention. If your eyes feel uncomfortable in your lenses, always take them out rather than pushing through it. 

What to do if you’ve worn your lenses too long 

If you realise you’ve been wearing your lenses longer than you should, don’t panic. Here’s what to do: 

13. Remove your lenses immediately. The sooner you take them out, the sooner your eyes can start to recover. 
14. Use lubricating eye drops to soothe dryness and help rehydrate your eyes. Choose drops that are safe to use with contact lenses or use them after removal. 
15. Rest your eyes. Give them time to recover before putting lenses in again. Switching to glasses for the rest of the day is a sensible move. 
16. Store your lenses correctly if you plan to use them again. Replace the solution in your contact lens case and follow the cleaning guidelines for your lens type. 

When to seek urgent medical attention 

Most cases of overwearing resolve on their own with rest, but you should see an optician or GP promptly if you experience any of the following: 

17. Severe eye pain that does not ease after removing your lenses 
18. Sudden or significant changes in vision 
19. Increased sensitivity to light 
20. Discharge from the eye, particularly if yellow or green 
21. Redness that gets worse rather than better after 24 hours 

 These can be signs of an infection or more serious corneal damage. Do not ignore them or wait to see if they pass. 

How long should you wear contact lenses each day? 

The right wearing time depends on your lens type and your eyes, but as a general guide: 

22. Daily disposable contact lenses: up to 8 to 12 hours is typically recommended for most wearers. 
23. Monthly and two-weekly lenses: similar daily wearing times apply, though comfort levels can vary depending on the lens material and your eyes. 
24. Extended wear lenses: some lenses are specifically designed and approved for continuous wear, including overnight use. These are not the same as simply leaving any lens in for longer than it’s designed for. 
     

It's worth remembering that wear time and replacement schedule are two different things. If you're wearing daily contact lenses, the 8 to 12 hour guide is your daily limit, and the lenses themselves are thrown away at the end of that single day, no exceptions. If you're on monthly contact lenses or two-weekly lenses, the same daily wear-time guidance applies, but you'll also need to retire the lenses themselves once their replacement date is up, even if you haven't worn them for the full 30 days. Overwearing isn't just about hours in your eyes on a single day; it's also about pushing a lens past the point it's designed to perform safely. 

 It’s also worth noting that extended wear contact lenses are a specific category of lenses made from highly oxygen-permeable materials that allow your eyes to breathe even during sleep. If you’re interested in extended wear, speak to your optician to see whether your eyes are suitable. Overwearing a standard lens is very different from wearing a lens that’s been specifically prescribed for overnight use. 

How to avoid overwearing your lenses 

A few simple habits can go a long way towards protecting your eye health: 

25. Set a reminder to remove your lenses at the same time each evening. 
26. Keep glasses nearby so switching is easy, especially if you’re likely to fall asleep on the sofa. 
27. Follow your lens replacement schedule carefully. Wearing lenses beyond their replacement date increases deposit build-up and the risk of complications. 
28. Never sleep in lenses unless they are specifically prescribed for extended wear. 
29. Read our full contact lens wearing guide for tips on keeping your eyes comfortable and healthy. 

FAQs 

Is it bad to wear daily contact lenses for more than 12 hours? 

Most opticians recommend wearing soft daily lenses for no more than 8 to 12 hours at a time. Going beyond this reduces oxygen supply to the cornea, which can cause redness, irritation, and a higher risk of infection. Listen to your eyes: if they feel uncomfortable before the 12-hour mark, take your lenses out. 

What happens if you fall asleep in contact lenses? 

Sleeping in contact lenses significantly reduces the oxygen reaching your cornea and increases the risk of infection. If you wake up still wearing lenses, remove them carefully, use lubricating drops if your eyes feel dry, and rest your eyes with glasses for the day. If you experience ongoing pain or redness, seek advice from an optician. 

Can wearing contact lenses too long cause permanent damage? 

In most cases, occasional overwearing causes temporary discomfort with no lasting effects. However, repeated or severe overwearing can lead to corneal infections, scarring, or corneal neovascularisation, which may have longer-term implications for your eye health. If you’re regularly wearing lenses beyond the recommended time, it’s worth discussing this with your optician. 

How do I know if my eyes are recovering properly after overwearing? 

Mild redness and dryness should improve within a few hours of removing your lenses and resting your eyes. If symptoms persist beyond 24 hours, worsen, or are accompanied by pain, discharge, or vision changes, contact your optician or GP. 

Are some contact lenses better for longer wear than others? 

Yes. Silicone hydrogel lenses allow significantly more oxygen to pass through to the cornea compared with older hydrogel lenses, which makes them a more comfortable choice for longer wearing days. If you regularly wear lenses for extended hours, your optician can help you find the right lens for your lifestyle. Browse our range of daily contact lenses and monthly contact lenses to find your fit.