The eyes of the nation will be on the eyes of the horses at Pimlico today in the 103rd running of the $188,700 Preakness takes. Or they should be, judging by prerace comments.

"Affirmed will have to run his eyeballs out to beat Alydar again," says Laz Barrera, trainer of the Kentucky Derby hero.

"I feel Alydar can wear Affirmed down in a drive," says Calumet trainer John Veitch, "I think we can look him in the eye and win."

"I hope those two eye each other so much they forget we are in the race," says Woody Stephens, trainer of Believe It, the Derby's third.

The owners and trainers of Track Reward, Noon Time Spender, Indigo Star and Dax S., the other four entrants, just say "Aye, aye" when confronted with the names, and the talents, of the top three.

The official chart caller may have to coin a new term should today's winning margin be, say, half a head. In that case, "First by an eye" would do instead of the conventional nose, head or neck.

"I believe in an eye for an eye," Vietch repeated yesterday. "Affirmed beat us fair and square when we were favored at Churchhill Downs. We hope to return the compliment.I would like to see the two horses hook up during the race and drag each other over the finish line.

"Alydar beat Affirmed twice the last year by blowing past him. This year he has grown enough - he's so much bigger and stronger - I think he can hook him and beat him. And, frankly, I think Barrera would like nothing better than for Affirmed to win the same way."

Alydar never came close enough to Affirmed in the Derby to establish eye contact. The margin was 1 1/2 lengths. The chart has Affirmed "fully extended" but Steve Cauthen commented he had "something left" on the winner at the wire and most observers agreed.

Jorge Velasquez, Alydar's jockey, contended that the Calumet colt "couldn't get hold of too late. Alydar was 17 lengths off the lead on the back side.

Two possible important changes have occured since these arch rivals met in Louisville two weeks ago. Veitch has drilled Alydar in a dynamite 1:10 2/5 and :35 and Affirmed may have lost a pound or two that he didn't have to spare.

Basically, the Preakness appears to be an ideal place for Affirmed to ratify his first victory in the Triple Crown series. The distance is a 16th of a mile shorter, 1 3/16 miles: the turns are a trifle tighter, the field is smaller (seven versus 11) and there is an absence of dangerous early speed such as Sensitive prince possessed in the Derby.

Post time for the race is 5:30 p.m. with coverage on WJLA-TV-7 between 5 and 6 p.m.

"Affirmed is the speed, and he will be calling the tune," Veitch admits.

"My horse has not had to change; he has not had to adapt to a special situation," Barrera notes. "He should be able to run his race, as he chooses. Alydar is the one that must change his pattern."

This means young Mr. Cauthen will be sitting chilly, policing the pace, while Velasquez cannot afford to sit back and wait to deliver the telling late punch that is Alydar's trademark. Alydar will have to go after Affirmed comparatively early.

The Pimlico crowd of 70,000 plus is going to bet that Affirmed is the superior thoroughbred, in this particular situation, at 4 to 5 versus 8 to 5.

Believe It rates about 5 to 1, with the four others a longshot player's or lottery lobbyist's delight.

It may be important to note that, in addition to winning five of their seven races, Affirmed prevailed in all three of the close finishes. He defeated Alydar by a half-length in the Hopeful at Saratoga, by a nose in the Futurity at Belmont and by a neck in the Laurel Futurity.

If, as history suggests, the preakness often develops into more of agut race than the Derby. Affirmed would appear to be beautifully equipped, judging by past performances, for another test of courage.

Believe It probably is good enough to win four out of five Preakni. His problem is his birth date, which places him in the same generation as A & A.

"The top two are exceptional, no doubt about it," Barrera agrees. "Tell me when two top colts such as this have run against each other so often and each one has run so well each time? There has never happened before. These have to be the two best since 1973, Secretariat and Sham."

Calumet is sending out its 14th preakness starter, Citation, Fabius, Tim Tam and Forward Pass won. Barrera saddled Derby winner Bold Forbes in the 1976 Preakness. Bold Forbes finished third to Elocutionist and Play the Red after outgunning Honest Pleasure through six furlongs in a suicidal 1:09.