If you go to "Find" and drop down to "People: Search" , then go to #2 for Surname Search, and enter the surname, you should find 11 with the Lysaght surname. At least two are from counties in Ireland. An alternative spelling is shown as well.
familysearch.org/search showed this: familysearch.org/pal:/MM9.1.1/N4F3-5JN familysearch.org/pal:/MM9.1.1/NWMX-KMF familysearch.org/pal:/MM9.1.1/FGDG-KG7 familysearch.org/pal:/MM9.1.1/N4FL-Y4Q
There's more at that site, if you want to check them out.