Quantitative Characteristics of the Prediction Relative Error in PL and PLUS Samples. Considering the PL Sample, the Median Error Indicates that for at Least Half of the Participants, the Error is Less than 12.5%. In the Case of the GBT-Based Model, the Low Level of the First Quartile Indicates that for Every Fourth Person, the Error is Less than 2.8%. Hence, for a 100-Year-Old, Age Estimation Based on Retinal Morphology Would Not be Incorrect by More Than 3 Years.