I know our brain somehow managed to upright the inverted images our eyes sees, also there's tons of optical illusions out there that are based on what we knew and experienced. Then if those so called calibration were never existed in the first place... would the old man sees any optical illusion for the first time when his blindfold is removed? Also can technology be used to recalibrate our brain to see through all optical illusions?
No, the person would be functionally blind. Experiments have already been conducted with animals (dogs) EDIT: as I was reminded it was CATS raised from birth in visually deprived environments that prove the visual cortex needs exposure to stimulus in order to grow, develop and function normally like all other parts of the brain. Deprive it of that stimulus and the brain will divert resources to other senses in order to compensate. 2nd EDIT: depending on how long the 'old' man lived there might be some improvement in visual acuity but it is still extremely unlikely the man would 'see' anywhere near normally before he died.