Do you drink milk past the expiration date?
Not likely, and if you do you're probably not happy about it. Contact lenses are tiny thin pieces of hydrated plastic that, like every other material in the world, are not impervious to getting dirty. Despite pharmaceutical companies' best efforts to create the perfect cleaning systems, even the best cleaning agent (hydrogen peroxide based systems) for both contact lens and ocular surface still doesn't clean everything. Protein sticks to the contact lens surface and over a period of days to weeks will denature or break down. This denatured protein does not agree with the ocular surfaces and can cause a host of complications that may not have immediate symptoms or signs.
17 million people in the US alone have Contact Lens Induce Dry Eye or CLIDE (Ramamoorthy P, 2008). The peak age of contact lens wearers is in the mid-20's and 
How often do you change your oil in your car? How often do you and your eye doctor discuss your eyes oil and how it relates to contact lens comfort and every day optical optimization? Japan is home to the world's highest number of LASIK surgeries performed at Shinigawa LASIK centers with over 1 million surgeries to date. In order to optimize visual and surgical clarity each patient undergoes LipiFlow thermal pulsation, a new standard for treating ocular surface disease - specifically dry eye. In December 2012, Shinigawa set a new standard in LASIK by treating 1000 patients with the LipiFlow system. This precedent shouldn't be isolated to those paying for premium refractive surgery. The amount of money you invest in contact lenses over a lifetime is likely more then you would pay for lasik, so why does the ocular surface not matter as much?
Proper maintenance and therapies for you eyelids, cornea and contact lenses are crucial for comfortable clear vision but the wide and sometimes careless availability of contacts through online stores and big box environments have turned contacts into a commodity and with that comes this pitfall - 'If I can shop around for the lowest price like a pack of gum then it must not be worth taking care of. Right?' But are your eyes a commodity that is as easily replaceable? If you knew 10 years from now that you wouldn't be able to tolerate your contact lenses would you do something different today?
Here's what you can do:
1) Wear single use lenses otherwise known as daily disposables Get rid of your case and solution and use it once and then toss it. The healthiest contact lens is no lens at all. The second healthiest is a daily disposable - sterile fresh lenses in the eye every day.
2) Treat your eyelids well - if you wear make-up, smoke, work in an office or use a computer for more then 4 hours a day then statistically your eyelids and blink are likely to be contributing to lid disease down the road. Talk to your doctor about ocular surface health and options for maintaining it. How often do you get a facial? Your eyelids deserve the same!
3) Don't shop downwards. Consider your contact lenses and vision choices the way you would consider LASIK - you would make your decisions based on risk, doctor experience, equipment safety and statistical likelihoods first before looking at price. Just because you can find them cheap online, does not mean they were created equal.
SideNote: LipiFlow is available in Canada
LipiFlow is the only FDA approved in-office procedure that has demonstrated clinical effectiveness in treating the ocular surface, specifically meibomian gland dysfunction (MGD). Although offerred to pre-operative patients going through lasik and cataract surgery in large refractive surgery centers, eyeLABS dry eye clinic is dedicated to the ocular surface and is located in Brampton, Ontario. A 12-minute non-surgical procedure has provided patients with relief of symptoms for up to 15 months as reported in clinical trials. Making this available to everyone will make a difference to contact lens wearers and non wearers alike - Dr. Maharaj is the first optometric clinic in North America to acquire this technology.