I was in the DLT a few weeks ago with my ex-Thai gf and there was this old woman, must have been 80 or older doing the tests and she failed every one including colour blindness, reaction and depth perception.
License was still granted however, I saw a staff member give it to her with my own eyes, along with all the sycophantic waiing and bowing to a much older person.
They will never improve the driving standards here, it is far beyond their intelligence, will and ability.