Eyes with "vertical line" pupils as opposed to circular, indicate a nocturnal lifestyle.
In response to your original post's pictures, the first shot is taken during the day in bright light while the snake is sleeping, the second was probably taken at night using a flash, when the pupils will be more dilated to take in more light
Paul
In response to your original post's pictures, the first shot is taken during the day in bright light while the snake is sleeping, the second was probably taken at night using a flash, when the pupils will be more dilated to take in more light

Paul