Figure 3. Lens transparency as a function of age. A: Dark-field images comparing lens transparency in WT and GPX1^−/− mice at 9, 12, 16 and 24 months (M) of age. Lens refractive alterations as aberrations started around 9 months of age and continued. As age progressed, loss of lens transparency increased and manifested as mature cataracts in GPX1^−/−, signifying the role of GPX1 for lens transparency. The increase in the loss of lens transparency is statistically significant compared to the age-related loss of lens transparency in the WT type. B: Quantification of pixel brightness intensity to assess lens transparency. The higher the pixel brightness intensity, the lower would be the lens transparency. At each point, GPX1^−/− mouse lenses showed a significant (p<0.01) increase in the severity of cataracts compared to WT lenses. Eight lenses were used for each mouse model. Error bars represent standard deviations.