About 52,000 applicants have received offers of places at third level from the CAO today.
A CAO spokesperson said that more than 14,000 people logged onto the system shortly after 6am and around 10,000 had already accepted an offer.
Changes to both the points and Leaving Cert grading systems have contributed to fluctuations in the points requirements for the majority of courses.
While points are down for more than half of all courses, in the case of around 40% they have risen.
Many STEM-related courses have seen a fall in their points requirement.
The points for general science degrees are down at UCD, Trinity College, DIT and NUIM.
The points for many engineering-related courses are also down considerably.
General Engineering is down by 44 points at NUIG, by 36 points at UCD, and by 30 at Trinity.
These decreases follow a drop earlier this year in the number of students applying to courses in many STEM areas.
A former president of the Institute of Guidance Counsellors has said the new grading system has culminated in a "cooling down of the points race".
Betty McLaughlin said it meant a record number of students are receiving their first choice this morning.
It reverses a trend seen in recent years which saw demand, and the points for such courses, rising steadily.
This year's fall in demand will be of concern to the Government and to others working to promote areas such as science and technology as positive career choices for school students.
Other areas that have seen a drop in their points requirement include nursing and teaching.
At DCU, nursing is down 25 points. Trinity, UCD and UCC have also seen a fall in the points required for their nursing courses.
This, too, is largely the result of a reduction in applications.
Applications to nursing courses fell by 5% this year.
This may be due to concerns around low pay for new entrants to the profession, as well as difficulties securing jobs.
Primary teaching has seen points fall for the second year running.
Teaching is another area where low pay for new entrants has been the subject of much recent controversy.
Primary teaching at Maynooth University is down by ten points.
DCU's main primary teaching course, the former St Patrick's College course, is down by three points to 462, while the points required of DCU teaching applicants who are Protestant has fallen by 15 points, to 420.
This is the second year that DCU will offer primary teaching applicants two separate entry routes, based on the applicant's religion, for what is largely the same course.
This is because courses formerly offered by separate Catholic and Protestant controlled colleges have now been absorbed into DCU.
The Mary Immaculate primary teaching course in Limerick has seen a one-point rise.
Many business courses have seen a rise in points.
Commerce is up by five at UCD, and by seven at NUIG.
Business, Economic and Social Studies at Trinity College is up ten points.
There are always a number of factors that contribute to points changes year-on-year.
They include the popularity of an area of study, as well as the number of places available.
But this year's changes to both the Leaving Certificate grading system and the points scale will certainly have added to the many changes points rises and falls seen this year.
Thousands of offers already accepted
CAO spokesperson Eileen Keleghan said that thousands of offers had already been accepted.
Speaking on RTÉ's Morning Ireland, she said some applicants will receive more than one offer but can only accept one.
She urged students to stay calm if they have not received their first offer, saying it is important to remember that there are a number of options available.
Round two offers will be made on Thursday, 31 August. Generally, around 2,000 offers will be made in that round.
Ms Keleghan said that a student accepting an offer in the first round will not prevent them from being offered a higher level offer in future rounds, if they are eligible.
Anyone who wishes to defer their offer needs to contact the institution directly because the CAO does not handle deferments.
Offers can be accepted online or by post.
The deadline for acceptance of round one offers is next Monday.