Is it okay to sleep in my contact lenses?

Unless you have specific contact lenses that are approved for overnight wear, it is NOT OKAY to sleep in your contact lenses!  When you sleep in them a few things happen: bacteria adhere to the lens surface and increase your risk of eye infection, your eyes dehydrate and the contact lens can cause small abrasions, and most commonly, your eye doesn't get enough oxygen (your closed eyelids when you are sleeping means that your cornea doesn't get as much oxygen as when your eyes are open).  When this happens, you can develop serious infections that can cause discomfort, light sensitivity, scarring and even blindness.

Related: What is the harm in extending the life of my contact lenses?

Why is my contact lens prescription different than my eyeglasses?

Contact lens prescriptions can be different from glasses prescriptions for a few reasons:


  • The optical center of a pair of glasses is usually located about 12mm away from the front of the eye but a contact lens sits directly on the eye. For some people, this seemingly insignificant distance can actually change the optics of the prescription (In general, higher prescriptions are affected more than lower prescriptions).  Since the optometrist measures your prescription approximately 12mm away from the eye, the contact lens prescription will often need to take this into account.
  • Another reason there is a difference is due to astigmatism.  Astigmatism basically means you need a different prescription in one direction (ie: horizontal) than in the other direction (ie: vertical).  If this difference is small, the tear film between the contact lens and the cornea can correct the astigmatism. If it is a larger amount, the contact lens needs to be calculated for rotation and fit to compensate for the astigmatism.  Glasses sit predictably on the eye (the ears and nose help the glasses stay stable in a predictable spot), so the prescription does not need to be adjusted for tear film or rotation.



What is the harm in extending the life of my contact lenses?

Extending the life of your contact lenses is kind of like driving a car at 250 km per hour.  For a while, if everything goes smoothly, there is no indication of trouble.  However, if something starts to go wrong, it can go wrong in a major way very quickly. 

Some complications that can occur are:

  • Allergic Reaction – protein build-up on the lens can cause discomfort, itchiness, dry eyes and intolerance to contact lens wear.
  • Conjunctivitis – accumulated protein attracts bacteria which can easily lead to conjunctivitis.  Symptoms include redness, burning, itching, tearing, light sensitivity, blurred vision and mucous discharge.
  • Corneal Edema (swelling) – Extended contact lens wear decreases the oxygen supply to the cornea and can cause increased fluid in the cornea. It can cause blurred vision and halos around lights.
  • Neovascularization – The cornea normally doesn’t have any blood vessels. When it is deprived of oxygen (by over wearing contact lenses), the body responds by growing new blood vessels, hoping to increase oxygen to the cornea. This abnormal blood vessel growth can interfere with vision. The new vessels are also weak and can hemorrhage and cause blindness.
  • Corneal Abrasion/Corneal Ulcer – Again, due to the lack of oxygen, the surface cells on the cornea become weak and easily damaged.  Corneal abrasions or corneal ulcers can form causing very serious infection and complications that can lead to blindness.

These complications can be caused both by wearing a contact lens too long in a day (or overnight) or by not replacing your lenses according to your optometrist's recommendations.  Either way, the eye is subject to less oxygen and more irritation and bacterial growth.  The blurred vision, pain, light sensitivity and potential scarring can be greatly reduced or eliminated by responsible contact lens wear.  If any of these symptoms occur, remove your contact lenses immediately and get checked by your optometrist.

*Image found here

Teens and Contact Lenses

If your child has healthy eyes, they are motivated, can follow instruction and can be trusted to take care of them, than we can teach almost anyone to wear and take care of contact lenses.

Contact lenses will not make their vision worse, and they will not become lost behind their eyes. Contact lenses can in fact be a safe and healthy addition or alternative to eyeglasses when worn responsibly. They are great for children who are heavily involved in sports, drama classes, or are hard on their eyeglasses.

For many children 1-Day disposable contact lenses may be a great alternative to conventional 2-week or 1-month disposable contacts lenses. There is no cleaning, no solutions, and no dirty lens cases to clean. If they accidentally lose or tear a contact lens, it’s no big deal, just grab a fresh one.

If your child is excited to try contact lenses, please book them in for an eye health examination and contact lenses fitting with one of our optometrists. 

eye-bar carries 1-Day disposable trial contact lenses by Ciba Vision, Acuvue, Cooper Vision and Bausch & Lomb.

Image via: Ciba Vision

eye-bar optometry in Sherwood Park - Eye Exams, Contact Lenses, Emergency Visits & Ophthalmology Referrals

Eye Care Question of the Week: #7


Are there any alternatives to laser eye surgery?


If you have been seriously contemplating going for laser eye surgery then this is an important question to ask yourself. This topic is also of interest for anyone who has already inquired about refractive surgery options but has been denied for any number of reasons: age, unstable prescription, thin corneas, high farsightedness or high nearsightedness, etc. Most patients who present to our clinic for a preliminary laser eye surgery consultation are looking to get away from eyeglasses. This may be for cosmetic reasons, lifestyle, or occupational requirements.  But do you know some of your alternatives?

One alternative to laser eye surgery is overnight or continuous wear contact lenses such as the Air Optix Night & Day by Ciba Vision. This product is one of the most studied contact lenses in the world and has a proven track record. For the right candidate this type of contact lens can offer excellent vision quality. Also, if your prescription changes you can quickly update your contact lens power as opposed to having to go through a laser eye surgery enhancement procedure. The other benefit of overnight contact lenses is that you know instantly how well you’re going to see, as there is no waiting period or healing time. From a financial perspective, an annual supply of these contact lenses is about one tenth the cost of laser eye procedures. On the downside however, there is still a small chance of developing an eye infection from sleeping in an overnight contact lens. Also, these contact lenses do not provide correction for astigmatism, which means that about 20% of patients are unable to wear them.

Another alternative to laser eye surgery is 1-Day disposable contact lenses, such as Dailies Aqua Comfort Plus or Acuvue TruEye. For many contact lens patients it’s simply the hassle of taking care of their contact lenses or forgetting when they last changed them. For these individuals a single use 1-Day disposable contact lens may be a great alternative. 1-Day disposable contact lenses also show a reduced prevalence of eye infections when compared to continuous wear overnight contact lenses or traditional 2-Week or 1-Month disposable contact lenses. These contact lenses may also be a great alternative for patients who suffer from dry eye syndrome and are not a candidate for overnight contact lens wear. Once again, an annual supply of these contact lenses are about one tenth the cost of laser eye surgery procedures, and your prescription can be quickly be updated.

To book a preliminary laser eye surgery consultation or to discuss some of your alternatives, please book an eye health examination with one of the optometrists at eye-bar.


eye-bar optometry in Sherwood Park - Eye Exams, Contact Lenses, Emergency Visits & Ophthalmology Referrals