Voters are choosing between retaining the Eighth Amendment, which says an unborn child has an equal right to life as the mother, or replacing it to include provision for "the regulation of termination of pregnancy".
People hold "yes" placards as the country heads to polling stations, May 25, 2018 in Dublin, Ireland. "Hopefully, our day has come", she said, outside a polling station opposite Dublin's cathedral.
But in the small town of Kilcullen, some 50 kilometres (32 miles) southwest of Dublin, voter Sean Murphy said: "I don't see any reason to change from the position we are in at the moment".
Vera Rooney cast her ballot at the same polling place.
"I took it really personally, this vote".
After weeks of anticipation, acrimony and more than a little heated discussion, Irish voters are finally casting ballots Friday to decide a simple yet deeply divisive question: Should the country repeal a constitutional amendment that bans abortion in almost all circumstances?
Under the current law, an unborn child has the same right to life as the mother.
Voters have headed to the polls all day to vote in the historic referendum that will potentially give women back their freedom of choice.
Women accessing illegal abortions can receive a maximum 14-year jail sentence, but the law allows them to travel overseas for an abortion, resulting in several thousand Irish women travelling to the United Kingdom each year to terminate their pregnancies.
"Not taking anything for granted of course, but quietly confident", he said.
"The fear of a lot of people on the No side of the campaign is that every time you take the step we are being asked to take, you change the culture of the country".
More than 3.2 million people are eligible to vote in Friday's referendum and officials said early turnout was greater than usual.
Prime Minister Leo Varadkar speaks to the media after casting his vote. The procedure is banned, though, even in cases of rape, incest or fetal abnormality.
Flynn, 48, said the experience left her feeling isolated, filled with shame, and excluded.
She and her family all voted yes, but she is still nervous of the result.
She said her vote would be one for solidarity and compassion, "a vote to say, I don't send you away anymore". Of course, the exit poll may be wrong, but it is hard to imagine that it could be wrong enough to call the final result into question.
Letters to the editor published in the Irish Independent newspaper contained several emotional arguments urging voters to reject the repeal movement.
And a recent Times/Ipsos MRBI survey revealed that among pro-abortionists, approval is conditional with 30 percent saying Ireland's abortion referendum goes "too far" with unrestricted access in the first 12 weeks.
"I will be voting no".
If the repeal effort is successful, the government has vowed to introduce legislation later this year to establish the circumstances under which Irish women may pursue the procedure.