Plenty is doing.
"Eye-movement dysfunctions, detectable during smooth pursuit but not during saccadic movements, occur in a majority of schizophrenics and in about 45% of their first degree relatives.... [My evidence is that] when considered together, schizophrenia and eye-movement dysfunctions can be accounted for by a single autosomal dominant gene."
Disclaimer: this quote appears here only to spark discussion. It is not endorsed one way or the other. Make up your own mind. Or just refresh the page for another viewpoint. From a collection assembled by the late Chris Brand.