Age dependence of freezable and nonfreezable water content of normal human lenses.

The cortex, intermediate zone, and nucleus of 19 normal human lenses between the ages of 3 and 77 yr were investigated. The freezable water content of the lenses was obtained by differential scanning calorimetry. The total water content was measured by vacuum dehydration. The nonfreezable water content was calculated from these two measurements. The total water content of the nucleus and intermediate layers decrease with age, while that of the cortex does not vary appreciably. The nonfreezable water content of all three regions of normal human lenses decreases with age.