Table 1 Comparison of various factors between cosmetic and conventional contact lenses

From: A review of cosmetic contact lens infections

FactorsCosmetic contact lensesConventional contact lenses
Dispensing factors
Unlicensed vendorsPlano cosmetic contact lenses may still be perceived as cosmetic devices in certain countries and can be sold through unlicensed vendors [43, 44, 59,60,61]. Patients may neither be provided with adequate assessments or appropriate counselling [26, 46,47,48,49,50].Only licensed eye care professionals can prescribe conventional contact lenses for refractive purposes in many countries. They are able to instruct and counsel lens wearers regarding appropriate lens wear habits.
Counterfeit lensesCounterfeit cosmetic contact lenses have found their way into conventional supply routes. These lenses possess different lens properties [34]. Microbial contamination of unused lenses and lens solution within the original packaging has also been described [35, 36]. 
Lens factors
Lens tintingTinting applied to lenses through various techniques may result in visual disturbances [16,17,18,19,20].Light handling tints are often incorporated into lenses to provide increased user visibility. Handling tints have not been shown to affect vision or colour perception.
Exposed pigments and surface roughnessExposed pigments may induce toxic reactions, result in systemic absorption of chemicals and greater bacterial adherence [22, 24, 25]. Increased surface roughness, particularly in contact lenses with surface pigment may result in discomfort and mechanical trauma, decrease lens wettability, and facilitate adherence and proliferation of microorganisms and protein deposits [27,28,29,30,31,32,33]. 
Patient-related factors
DemographicsUsers are more likely to be younger, female and emmetropic [3, 8, 9, 32, 62]. 
Lens wear experienceCosmetic contact lens wearers are likely to be contact lens naïve and may incorrectly assume that cosmetic lenses are accessories that do not require proper lens evaluation, fitting and care [2]Contact lens users using lenses for refractive purposes are more likely to have undergone assessment by licensed eye care professionals.
Cosmetic agentsSimilar findings would be expected.Cosmetic agents used may adhere to the lens surface and alter lens properties despite cleaning. This may contribute to bacterial adherence and proliferation [63, 64].
Non-compliance with recommended lens wear habitsPatients are less likely to adhere to recommended safe lens wear practices and scheduled follow-up consultations [3, 44, 62, 65]. 
Wear frequencyInfrequent disinfection and replacement of contact lens solutions and lenses due to less frequent lens wear [2].