가열 온도가 높을수록, 굴절률이 높을수록 렌즈의 균열이 더 심하게 발생되었고 투과율도 감소하였다고 하였다.
It was said that the higher the heating temperature plus the higher the refractive index, the greater amount of serious the cracks of the lens occurred and the transmittance decreased.