Lenses were imaged using a charge-coupled device (CCD) camera (UVP, Cambridge, UK) equipped with commercial software (Synoptics, Cambridge, UK) at the experimental start point (day 0) and at 24-hour intervals throughout experiments. Brightfield illumination was used, with a black and white grid placed beneath lenses to assess visual quality and, therefore, lens clarity. Visual quality was quantified from these images by measuring standard deviation values of grayscale values obtained from the grid beneath the lens. Values of standard deviation of clear lenses are high, whereas when the lens becomes more opaque, the grid becomes less defined/homogenous and the standard deviation values decrease. A reference value for peak visual quality was determined for each image by selecting a region of the grid adjacent to the lens. This region exhibits the greatest standard deviation and best visual quality and thus a decrease was calculated relative to these values. Image analysis was performed with analysis software (Image-Pro Premier; Media Cybernetics, Inc., Rockville, MD, USA).