5 Reasons to NEVER Overwear Your Contact Lenses

How often do you throw away your contact lenses?  It is amazing the responses you can get on this simple question.  As an optometrist, I have had patients that have been wearing their same trial pair of contact lenses they were dispensed at an exam 2 years ago.  Most people aren't that daring, but it is not uncommon to have people wearing lenses for months longer than FDA guidelines recommend.  And most patients are very defensive  about just how often they are throwing their lenses away.  Why do I recommend following FDA guidelines for proper contact lens disposal?  Here are 5 very real complications that I treat on a regular basis that are a result of improper contact lens wear.

1) CORNEAL NEOVASCULARIZATION

New blood vessel growth is not a good thing when it means opacification of what should be clear tissue!  Picture via optometric.com

     Neovascularization means the growth of new blood vessels, which in itself doesn't sound so bad, right?  Well in the case of your cornea, it can have potentially devastating results.  The cornea is the clear dome of tissue where your contact lens sits, and the clarity is essential to your clear vision.  As a clear tissue, the cornea must receive the majority of its oxygen from the atmosphere.  When a contact lens sits on top of the cornea, this atmospheric oxygen must travel through the contact lens to supply the corneal tissue.  As a contact lens ages, the amount of oxygen to the eye gradually decreases until it reaches an unsafe level (which coincides with the FDA required disposal time, be that monthly or bi-weekly, or daily).  What happens if you continue to wear the lens past the time that it is supplying adequate oxygen?  Well the cornea has to get oxygen somehow, so it grows it's own blood vessels.  With time and repeated insult, your cornea could end up looking like this: 

A cornea with significant scarring and neovascularization

  Treatment = Change to more oxygen permeable contact lenses or daily wear. If severe enough, contact lens wear may have to be discontinued permanently.

2) GIANT PAPILLARY CONJUNCTIVITIS

GPC: a nasty allergic response to your contact lenses

    GPC is one of the most common acute conditions I see from contact lens overwear. What will you notice? Increased discomfort with your contact lenses, and even worse irritation when the contact lenses are off.  Many of my patients complain of excessive movement with their contact lenses (that has just recently occurred).  The large bumps pictured under the eyelid are papillae, which are an acute allergic inflammation that the body mounts against any protein build-up on the surface of the contact lens.  

Treatment = No contact lens wear for 1-2 weeks, prescribed eye drops (typically a steroid if advanced or antihistamine drops if mild)

3) CONTACT LENS ACUTE RED EYE

Acute red eye, usually after sleeping in contact lenses is classic for CLARE

    Commonly abbreviated as CLARE, this acute onset red eye is also a side effect of poor oxygen levels to the cornea.  Remember that the cornea receives most of its oxygen from the atmosphere, so when you sleep and your eyelids close, you are depriving your cornea of oxygen to some degree.  Now put a contact lens on the cornea, and those levels go dramatically down.  This is why most doctors NEVER recommend sleeping in lenses as the ideal form of contact lens wear, and when you do sleep in your contact lenses you need to be prescribed a special contact lens made for extra oxygen delivery. If you have CLARE, you will wake up with red, irritated, watery eyes.  Best thing to do is take those contact lenses out and throw them away!

Treatment = No contact lens wear for around 1 week.  Drops prescribed as needed

4) BACTERIAL ULCER

A Bacterial Ulcer: definitely something you do NOT want

 If the picture isn't enough to sway you, let me just emphasize the fact that you do NOT want a corneal ulcer. They are painful.  They are really nasty looking.  They cause permanent scarring.  They can take a very long time to heal up.  Did I mention they are VERY painful?  Corneal ulcers come in all shapes and sizes, and most are smaller and located more towards the periphery.  When I do see a large central ulcer, that means immediate referral to a corneal specialist.  If your ulcer is anywhere near your pupil (where light passes through to allow you to see), then you are going to have a permanent scar obstructing your line of sight!  Where do these ulcers come from?  Like most of the problems we've discussed, a lack of oxygen is a trigger.  When the cornea is deprived of oxygen the integrity of the tissue is weakened.  Bacteria on your contact lenses can then penetrate the cornea and result in the ulcer.  

Treatment = No contact lens wear for several weeks (or indefinitely depending on the severity).  Frequent antibiotic use (typically every hour round the clock in severe cases).  

5) YOU ONLY GET ONE CORNEA PER EYE.  FOREVER.

I frequently tell my patients who are overwearing contact lenses that their cornea has to last them to age 100.  You don't want to be depriving it of oxygen in your teens or twenties! Here's another question that I have heard doctors pose: "would you sleep in the same pair of undewear for months at a time without washing it?"  Your contact lenses are very prone to accumulating bacteria, so it is very important to properly clean them and throw them away at the end of their lifespan to ensure you aren't depriving your eye of the oxygen it needs.  

Take home points:

• If you have a red eye, remove your contact lenses and see your doctor.  Most of these conditions require a high powered microscope to properly diagnose.
• How much money are you really saving by overwearing contact lenses when you take into account that if you get a contact lens complication, the office visits and cost of medicated eye drops is very high?  Not to mention the fact that you will be causing permanent damage to the health of your eyes.
• If you wear contact lenses, you need a pair of glasses.  No exceptions.  If you can't see to drive legally without contact lenses, you MUST have back-up glasses.  I don't care how old they are.  They just need to be good enough for you to use in case you have a complication where you have to be out of contact lenses.