The paper presents elements of eye biometry theory and practice as seen by a young resident, in his first years of practice as ophthalmologist. The paper refers to the current stage of IOL measurement technique. Also, challenges for the younger generation are presented, such as new formulas for the patients who have undergone refractive surgery, measurement solutions for the patients affected by cataract, whose vitreous was replaced by silicone, and last but not least, the proper approach as regards biometrical measurements for children.