Digital Image Analysis of Surface Quality in Manufactured Flat Optical Lenses

The production of optical lenses demands stringent quality control to ensure compliance with international standards, particularly ISO 10110-7 for surface defects. Traditional manual inspection methods are labor-intensive and subjective, necessitating automated solutions. This study presents a cost-effective, microscope-based imaging system for defect analysis in plano-parallel lenses, integrating a high-resolution Euromex camera, Schoelly Flexilux LED illumination, and ImageFocus Alpha software. The system achieves a resolution of 0.8 µm/pixel, enabling detection of scratches ≥1 µm and pits ≥50 µm², while adhering to the 5% total defect area limit. Calibration with NIST-traceable standards ensures traceability, and automated workflows reduce subjectivity in defect assessment. Experimental results demonstrate successful defect identification, including chips and scratches, validated against reference etalons. The proposed system lays the groundwork for future AI-driven quality control, offering scalability for industrial applications.