Quantification of water content in contact lenses combining terahertz imaging and optical coherence tomography

Hydration of contact lenses is an important parameter as it governs the oxygen transport to the cornea. Dehydration of contact lenses during lens wear causes discomfort due to dry eye and alterations in lens fitting characteristics. Terahertz (THz) imaging and optical coherence tomography (OCT) together can provide unique information about the hydration profile of the contact lens and its structure. Here, we present results that combine the information measured from OCT and THz systems on contact lenses which aid in determining the change in water content and thickness over time. Overlaid THz and OCT images that align well are shown, making it possible to automatically scale and co-register the two data sets. Hence, we show that a combined OCT/THz system can deliver distinctive knowledge about the capacity of contact lenses to maintain their comfort and optical characteristics over time.