It depends on if the man has 2 alleles for normal vision, if he does then then there is zero percent chance, if he also has an allele for color blindness then its 25%.
In developed nations people have more fast food options which lead to cardiovascular disease. As well as screen time all day since this is one of the factors of cardiovascular disease. Undeveloped nations don't have fast-food or television to watch all day, since they play outside.