At its best "Short Eyes," which opens today at the Avalon 2, Lincoln 2 and Hampton Mall, generates more raw dramatic power than any other American film of the past year. The most remarkable sequence is a confessional monologue delivered with riveting conviction by Bruce Davison in the catalytic role of Clark Davis, an apparently innocuous white-collar twerp who becomes the whipping boy and victim of a cellblock of inmates when they discover that he is an accused child molester, a "short eyes" in their orgot.

Davis tries to account for his exual obsession to the only prisoner willing to hear him out, Jose Perez's thoughtful, paternal Juan, the cellblock sage and conscience. Davison transmits the distressing mixture of shame and uncontrollable desire in Davis' lines with a sincerity that intensifies the appalling candor and eloquence of the lines themselves. You feel as if you're bearing witness to authentically painful revelations.

In fact, the confession creates such a gripping mood that you almost wince when director Robert M. Young betrays an apparent inability to visualize the sequence with absolute integrity. He resorts to frequent cuts that insert Perez's reactions and momentarily lose sight of Davision. Each return to the speaker's pale, anguished face only underlines the loss.

Davison's performance is astonishing, a genuinely shocking exposure of human weakness. It must have transfixed the company and jumped out of the rushes. Terrible as the character's confessions are, you don't want his image to vanish for an instant. The performance continues to reverberate even when it's only a disembodied voice, but it's regretable that Young couldn't compose the sequence with this two actors sharing the frame.

Young shot the movie inside the Manhattan House of Detention, better known as The Tombs, so the immediate surroundings certainly support the stinging authenticity of playwright Miguel Pinero's idiom, persumably acquired during his own years as a prison inmate.

Pinero himself contributes a sharp performance as one of the least sympathetic inmates, the bearded, malicious little Go-Go, who suffers a rough form of justice after planting a weapon in the bunk of another prisoner. "Short Eyes" began as a theater piece at the Riverside Church and eventually progressed to the Vivian Beaumont Theater at Lincoln Center, collecting two Obies and the New York Drama Critics' Circle award in the process.

The insider's view of the systems of caste and selfesteem operating behind bars seems so accurate and scalding that one never doubts the social value of Pinero's text. "Short Eyes" may come as close of being a crime-deterrent as any stylized representation of a sordid slice of real life can never be.

It is, however, a diffusely strutured drama. The appearance of Clark Davis ought to be a more effective organizing device than it is. Instead of serving a truly pivotal dramatic function, like Hickey in "The iceman Cometh," Davis simply dominates the strongest episode in an eye-opening but rambling set of impressions from the inside.

Pinero hasn't devised a structure that can accomodate the dreadful ironies and implications involved in the inmates' victimization of Clark Davis. The most crucial issue - the need in most of the inmates to reject and finally brutalize the petrified, cowardly Davis - is obscured by subordinate plot elements and by a feebly ironic suggestion that he might have been locked up on bum rap. Still, the emotional undercurrents are too strong to be subdued. The text perfomances and settings evoke manifestations of violence, fear and misery that outlast the anticlimactic fadeout.

Davison's perfomance is in a class by itself among this year's dramatic work by American film actors in leading roles. The best male performances have been in a much lighter vein: Paul Newman as the devious coach in "Slap Shot" and Richard Dreyfuss as an ebullient actor in the upcoming "Tha Goodbye Girl." Davison's opportunity seems unique, and so does his achievement.

The most impressive members of the supporting cast, some of whose roles are probably longer than Davison's are Pinero, Perez. Joseph Carberry's as the sleepy-eyed but explosive white prisoner Longshoe. Shawn Elliott as the sexually wound-up Paco and Curtis Mayfield as the amiable Pappy, the victim of Go-Go's spite. Mayfield's participation, however, has also led to an extended musical interlude that puts a gratuitous lull in the middle of the film. One surmises that record sales will make the subterfuge seem worthwhile in the long run.