No, it isn't "ok." Sure people do it, but the majority of people also used to smoke around their kids.
The AAP recommends NO screen time at all for LO's under two for very good, we'll-researched reasons. Do you want to risk attention span disorders, nightmares, language delays, psychological problems, obesity or decreased ability to engage in self-directed play just because you couldn't be bothered to turn off the TV? Screen time is a slippery slope, and once you allow LO's to be entertained by digital media it is most likely a habits that your family will continue, escalating those aforementioned risks.
Go read for yourself:
http://www.aap.org/en-us/search/pages/results.aspx?k=Screen%20time