Eclipse folder has an initialization file which is used by eclipse on launch/Double click it is named as eclipse.ini. Add the following lines in eclipse.ini file. Where the vm defines the path of JVM with which we want eclipse to use.
-vm
C:\Program Files\Java\jdk1.8\bin\javaw.exe
Make sure you have add the above lines separately and above the following line
--launcher.appendVmargs
-vmargs