Profiles of the order parameter obtained at 37°C with phospholipid-analogue spin labels across PCD for cortical (A) and nuclear (B) lens lipid membranes of eye lenses from human donors of different age groups. Data for age groups 41–60 and 61–70 years are reproduced, respectively, from Reference 42, Copyright 2013, with permission from Elsevier, and from Reference 18, Copyright 2014, with permission from Springer Publishing. The approximate localizations of the nitroxide moieties of spin labels are indicated by arrows.