When you export the KPIs (option 2) using the KPIs button on the Till Screen the data is as follows:

KPIIncludes
Total SalesTotal Private Sales + Total NHS Sales + Invoiced To Sales – Written Off Amounts
Total ApptsTotal number of Appointment with a Time that doesn’t end in a 3 (Times ending in 3 are blanked out times)
Total Appts BookedTotal number of Appointment that have are booked
CL AppointmentsTotal Number of Appointments in the diary that are a contact lens type (ticked in Lists/Diary Notes as a CL)
Total NHS STsTotal Number of GOS1s put on the dispense screen
Total Private STsTotal Number of private sight tests put on the dispense screen
Extra Visit/Supp AppointmentsTotal Number of Appointments in the diary that are Extra Visits/Supp Tests (ticked in Lists/Diary Notes as a Extra Visit
No. Advised Specs (New Rx)Exams that have “New Rx” chosen on the exam screen
Full Exams Dispensed SpectaclesNumber of patients who had a full exam and were dispensed at least 1 pair of glasses.
Total Specs SalesTotal Private specs sales + NHS specs (GOS3 +4) sales + Invoiced To Specs sales
Total Contact Lens SalesTotal Private CL sales
Total Accessory SalesTotal sales of accessories from Sale Only plus patient dispense screen
Total NHS TakenGOS1s + GOS3s + GOS4s
Total NHS Exam FeesGOS1s
Total Pvt Prof FeesAll private exam fees
Number of S/V DispensesNumber of single vision distance + single vision near + single vision intermediate 
Number of Bif DispensesNumber of bifocal dispenses
Number of Progs DispensesNumber of varifocal dispenses
No. of ReglazesNumber of dispenses where the frame name has the word Reglaze in it eg Reglaze full rim, Reglaze supra etc
No. of Out RxDispenses where the Optometrist was noted as “Out Rx”
Total New PxsNumber of Dispensed Sight Tests for new patients
RefundsTotal amount of negative sales
RemakesNumber of dispenses where there is something in the “Remake” box at the top of the frames area
DNANumber of Patients who did not attend