SOP For validation of inspectors of optical checking of filled vials is described in this post which you can follow in the section of the Quality Assurance Department.

OBJECTIVE
This SOP lays down a procedure for validation of visual checking inspectors
SCOPE
This is applicable to the personnel assigned the job for visual checking during the filling/ packaging process
RESPONSIBILITY
Optical Inspector
Optical Supervisor
Production Pharmacist
QA Officer
ACCOUNTABILITY
Manager Quality Assurance
Manager Production
PROCEDURE
Select 100 filled vials which contains
  • 5 vials with poor sealing 
  • 5 vials with particulate matter 
  • 2 vials with molding defect, 
  • 5 vials with less or more volume
  • 2 vials with glass particles and 81 clear & good vials.
Mark all the vials with numbering from 1-100  on the cap with a suitable marker & make a list of all vials and write the remark like a good, sealing defect particle, module, volume to identify the vials on the sheet. 
This remark should be against the vial number and be filled in the form.
Ask each inspector to check the vial against black & white background & remove the rejected vials.
Acceptance Criteria
If the inspector rejects all the marked vials then they must pass the validation test.
If the inspector fails to identify minor rejection like small mold defect or minor sealing defect they must be considered to pass the test.
If the inspector fails to identify even one major defect like the suspended particle, glass particle, volume variation then they must fail in the validation
test.
A new inspector has to pass the validation test in two consecutive test then only in this case they must be allowed to check the vials.