Age-related cortical cataract
high lifetime exposure to uvr is associated with increased incidence of cortical cataract the paradox is that the most severe damage in cortical cataract occurs near the equator initially, the area most protected from sunlight by the iris. Cortical cataracts are associated with increased membrane permeability and ion transporters, pumps and exchangers are not able to maintain the homeostatic concentration. An increased concentration of Ca++ in the fiber cytoplasm also drives fluid accumulation. Affected regions of the fiber show disruption of structure and can include membrane rupture. The changes first occur in the center of the elongated fiber (that is at the equatorial region), with the apical and basal ends remaining transparent. Generally the tapered fiber ends, located at the suture in the optical axis, are only afeected very late in the life of the cortical cataract.