Silicone hydrogel materials have solved the problem of getting enough oxygen to the cornea; lens induced hypoxic changes are a thing of the past.
Dk/t is no longer a relevant measure in differentiating between silicone hydrogel materials both in terms of their oxygen performance and their comfort. All silicone hydrogels have high oxygen flux and all currently available lenses allow 100% corneal oxygen consumption.
Comfort is correlated with both the modulus and surface lubricity of the contact lens, the latter being the strongest relationship with improved comfort seen in lower modulus, lower friction materials.
Achieving a balance of properties in silicone hydrogels is key in order to deliver both health and importantly, comfort benefits to the wearer. Careful consideration of the balance of modulus and coefficient of friction (lubricity) should help in recommending more comfortable contact lenses for patients.
