"Green Eyes," on Channel 7 tonight at 9, is worth watching simply for Paul Winfield's performance as a Vietnam veteran who returns to Saigon to search for his Vietnamese mistress and their son.

But this ABC television movie is also compelling for its insight into the fascination we seem to have with the children of Vietnam.

We came away from the Vietnam war with two dominant visual impressions of children. One was the tiny girl running naked down a road while napalm exploded in the backround. The other was President Ford carrying a Vietnam orphan down the ramp of an airplane in California during "Operation Babylift."

"Green Eyes," in a manner fairly honest, at least by television's standards, dramatically combines the two images.

Winfield does not find his son. But in the end, he adopts one of the street-smart young boys who roamed Saigon during the war selling every thing from cigarettes to their sisters - an ending that fits perfectly into the "Operation Babylift" image.

But before that, as Winfield wanders the orphanages of Saigon - sent there by an English social worker well played by Rita Tushingham - we begin to see what scars our presence left on the social fabric of Vietnam. That impression fits the image of the girl running down the road with her back badly burned.

David Seltzer's fine script plus the performances by Winfield and Tushingham leaves the viewer with a disturbing sense of what ceremony of innocence was our intervention in Vietnam.

Throughout the two hours, I kept thinking of the line in Graham Greene's "The Quiet American;" "Innocence is like a blind leper who has lost his bell, wandering the world, meaning no harm."

This is a movie that will probably make a lot of us think about innocence run amok in a part of the world we have never really understood. Appropriately enough, it was filmed in the Philippines, that other great and enduring monument to an earlier form of American innocence.