Contact lens wear, under the appropriate conditions, is very safe and convenient. Unfortunately, it is sometimes difficult to determine whether our own eyes are being harmed by improper or over-usage of lenses. This is why it is extremely important to have an eye care professional examine your eyes on a regular basis to ensure that your ocular surface is healthy.
Corneal infection is the most serious complication arising from contact lens wear requiring immediate attention, and is associated with several risk factors. Overnight wear, poor lens case hygiene, lack of hand-washing, increased wear time, and smoking are some of the reasons why one may get a corneal infection from contact lenses.
Another complication arises from the fact that some contact lenses deprive the cornea of oxygen. The human body is quite resilient, and in the face of oxygen deprivation grows new blood vessels into the cornea to help feed it. Unfortunately, these blood vessels do not belong in the clear cornea and can eventually become sight-threatening. This process is called neovascularization, and your eye doctor looks carefully for its precursors and signs. Long-term contact lens wear can also result in actual distortion of the cornea by changing its thickness and curvature. This is not easily detected by the microscopes used in the optometrists office, rather it requires an instrument called a corneal topographer (eyeLABS uses the Oculus Keratograph corneal topographer). Although not every office has one, it is a very useful tool to detect subtle changes to the structure of the eye as a result of improper fitting or usage of contact lenses.