Can a child on Ritalin have constricted pupils?

I am an adult and I started to take Ritalin 4 days ago. Usually I have dilated pupil, but with Ritalin they are quite constricted. I looked around in my text books and it is supposed to be the opposite to pupil are supposed to be more dilated. I also took effexor last month and my pupils were extra dilated (almost completely black).

Yep I am not a professional, but it is very strange. Nevertheless even if with Ritalin my pupils are constricted my eye are very sensitive to light. My own theory will be that in some person Ritalin will increase the eye sensibility to light and than limit the amount by closing the pupil. Makes sense for me but I will still look around.