Length of Wear

• Contact lenses are either daily wear, which must be removed nightly and tossed, or extended wear, which can be worn overnight and for several consecutive days without removal. Extended or continuous wear lenses can be worn for up to 30 consecutive days. Wearing lenses longer than their intended use can cause infection and damage to the eyes.
  
  

Improper Cleaning

• It is very important to carefully store and clean contact lenses. Multipurpose solutions clean and sanitize the lenses so that dirt, debris and bacteria do not adhere to the lenses and infect the eyes.
  
  

Improper Fit

• Contact lenses must fit the eye properly or complications such as discomfort, poor vision or ulcers of the cornea may occur. The correct power, curvature and diameter are imperative for good vision.
  
  

GPC

• GPC, giant papillary conjunctivitis, is the most common problem resulting from contact lens use. It manifests as swelling on the upper eyelid and is evidence of an allergic reaction to the lenses.The eyes may become red, itchy and have a sticky discharge. Remove lenses until the symptoms disappear and your eye doctor has checked your vision.
  
  

Corneal Abrasion

• A corneal abrasion may occur if a tiny particle such as dust or dirt gets embedded under the lenses. It may also occur if there's a defect in the edge or a tear in the lens. Pain and discomfort may follow, but this does not always require medical attention. However, a deep abrasion, which causes extreme pain and light sensitivity, must be treated immediately.
  
  

Corneal Oedema

• Corneal Oedema occurs when there's not enough oxygen getting to the cornea. Improper wear of contact lenses is frequently to blame. Symptoms may include hazy vision and halos around lights when the lenses are removed. Often no symptoms are present. Regular checkups are the best prevention.