A SAS data set is exactly equivalent to the concept of a table (formally, a. âtupleâ) in the relational model. The programmer could use either data step MERGE or use a join. in PROC SQL. Which one to use can be a matter of personal preference. But if you learn each. method well, you can choose the best tool for each specific situation.
An eye twitch is an involuntary spasm of the muscles in the eyelid. Blepharospasm is the medical term for eyelid twitching. Eyelid twitching usually occurs every few seconds and lasts for a few minutes. It may come and go over a period of days or weeks. Sometimes the twitching results in the eye being held closed until the movement stops, but this is not always the case.
If eye strain results in twitching, be sure you get plenty of breaks during the day to help rest your eyes and reduce the severity of your symptoms. Other Names for that Eye Twitch: Also known as benign essential, blepharospasm, hemifacial spasm, eye spasms. 1  Massage Techniques for Eye and Muscle Twitches.