The most common complications arise from contact lenses are related to cornea.

Following is a list of corneal changes that can occur with contact lens use:

• Infectious keratitis/corneal ulcers:. This can be related to a poor lens fit, as well as improper contact lens care/hygiene.
• Corneal abrasions:. These can result from foreign bodies under a lens, a poor insertion / removal technique, or a damaged contact lens. Because contact lens use can increase the risk of infection, most clinicians treat abrasions with antibiotic eye drops and no patching.
• Punctate keratitis:. This finding can be related to a poor lens fit, a toxic reaction to lens solutions, or dry eyes.
• 3 o’clock and 9 o’clock staining:. This specific superficial punctate keratitis (SPK) staining pattern can be seen in RGP contact lens users and is probably related to poor wetting in the horizontal axis.
• Sterile infiltrates:. Typically these are seen in the peripheral cornea; often there is more than one spot, and the epithelium over the spots is intact. Discontinuing lens use can resolve the problem, but clinicians often prescribe an antibiotic, although cultures tend to show no growth.
• Contact lens superior limbic keratoconjuctivitis (CLSLK):. This finding is similar to superior limbic keratoconjunctivit is, with injection of the superior bulbar conjunctiva and palpebral changes in the overlying upper eyelid. Discontinuing lens leads to resolution.
• Dendritic keratitis:. The slit-lamp appearance is like that of herpes Simplex virus (HSV) keratitis, but the fluorescein staining is typically less intense.
• Corneal neovascularization:. This is usually a sign of hypoxia.  If neovascularization is extensive, it can lead to corneal scarring and lipid deposition or intracorneal hemorrhage.
• Corneal warpage:. Change in corneal shape from contact lens use has been reported with both soft and RGP lenses, but it is more commonly associated with hard lenses.
• Spectacle blur:. Corneal warpage and more temporary changes in corneal shape can change the normal spectacle-corrected vision immediately after lens removal. If patients complain of spectacle blur, the contact lens fit should be reevaluated and discontinuation of lens use for a period should be considered.
• Ptosis:. This problem is related not to corneal changes but possibly to dehiscence of the levator aponeurosis secondary to long-term use of RGP lenses.