When i exercise my vision changes went the cardiologist to see if it is my heart but it isn't. my heart is ok. some say is sinusitis. what can it be?

What do you mean?: Can you specify exactly what you mean by "vision changes during exercise." If you are referring to a blurring of your vision or double vision or changes of that nature after doing heavy physical exertion then, you may be suffering from a form of Uthoff'svphenomenon. In that case, a neurologist may be a helpful specialist to see as opposed to either an ophthalmologist or optometrist.