When fitting soft contact lenses, it is impossible to visualise the tear layer below the lens in white light. In addition, being permeable, soft lenses absorbs normal fluorescein and use of high molecular fluorescein is not sensitive enough to identify subtle changes in fit. This study provides a software tool based on a Finite Element Model of the human eye, developed over a period of more than 15 years at both Dundee University and Liverpool University, that can demonstrate the fit of a known contact lens design on a particular subject’s eye through computer simulation. Using this new technique, thickness maps for the tear layer under contact lenses can be created. These maps give important feedback to the contact lens fitting and design process and have the potential to enable the full customisation of contact lenses. In addition, the model itself can demonstrate how the lens settles onto the eye during the blink process, together with rebound from the corneal surface directly after the blink
