Some people have got the idea that President Reagan is not doing enough to mark the first national holiday of Martin Luther King Jr.

Well, someone needs to set the record straight. The president is doing plenty. I do not mean his visit to a predominantly black elementary school here on Jan. 15, King's actual birthday, or his presentation of a Congressional Gold Medal to the widow of King's late contemporary, Roy Wilkins, or his plans to meet with Mrs. Martin Luther King Jr.

No, I mean something that seems to have escaped notice. President Reagan issued proclamations last week setting aside two separate weeks in March: one to spotlight the importance of good vision and the other to emphasize poison prevention.

Don't you just love the sublety? If King stood for anything, it was for a clearer vision of what America is and what it can be, and for the prevention of the poison of racism.

Surely when he declared the week starting March 16 "National Poison Prevention Week" the president was sending a message to his subordinates at the White House who have been leaning on him to repeal the affirmative action executive order honored by every president since Lyndon Johnson.

The president, I must assume, was trying to tell Attorney General Ed Meese and Assistant Attorney General Brad Reynolds they should stop spreading the malicious poison that the executive order is a call for racial quotas, or that it has been a pragmatic failure.

It was, I imagine, the president's way of reminding his top law enforcement officials that the affirmative action order they want to disembowel explicitly prohibits the use of quotas.

It has been interpreted to promote goals and timetables, but what (the president must have wondered) is wrong with that? If it is demonstrable that, despite the tremendous progress America has made in racial fairness since the days of Dr. King, minorities still fall short of equal opportunity in hiring and promotion, doesn't it make sense that we ought to have as a goal the ending of that disparity of opportunity? Isn't it reasonable to set a timetable, by which that goal -- not "quota" -- might be attained?

Perhaps the president saw a copy of the speech delivered in Atlanta last Wednesday by Hyman Bookbinder of the American Jewish Committee (which is strongly opposed to quotas) in which that former ally of King had this to say:

"Even as we were winning legal battles for fair employment, in the '50s and '60s, Dr. King and others were telling us that legal victories alone would not suffice, that 'affirmative action' would be required to make a reality of legal victories. The phrase 'affirmative action' started to appear explicitly in presidential speeches and executive orders, in agency regulations, in civil rights advocacy. . . . It has meant improved training and retraining programs, critical review of testing and qualifying systems, changes in recruiting and advertising campaigns, better labor market information, better education and counseling and upgrading arrangements and (later) setting realistic goals for equal employment."

But the president, perhaps understanding that some Americans -- including some in his administration -- are unable to see this plain truth, announced that the week starting March 2 will be "Vision Week." We not only need to rid ourselves of the meanness that still poisons the society, he seemed to be saying, but also to improve our vision so that we can see the size and shape of the barriers that remain.

Don't you imagine he was making a veiled reference to the ploy now being considered at the Office of Management and Budget to put an end to the collecting of racial data on government subcontractors? Without the numbers, the president must understand, enforcement is impossible.

While the rest of us have been searching for a way to summarize the magnificent work of America's hero, Reagan has gone straight to the heart of what he was about: a clearer vision and an end to the spread of poison. The Great Communicator has done it again.