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Recently I had my windshield replaced by an auto glass company due to an accidental flying object.

I noticed afterwards that at night the windshield tends to magnify the diameter of headlights, from oncoming vehicles, across the windshield causing distraction and eye strain. This phenomenon was not apparent with the original windshield.

I have approached the Manager of the auto glass company concerned about this problem who proceeded to give me a sales lecture on how much better the screen quality was compared with the one removed. The replacement screen is non genuine and is sourced out of China

I challenged him to have a drive at night in the car to see for himself. This headlight diffusion problem is also accentuated when raining.

My question is; are there any industry standards for measuring this diffusion, or accentuated refraction of light rays?.

If not what do you suggest I do about it?

Ross

From the "Ask Jack" archives - 23 July, 2010

The fact the glass is non genuine and comes out of China is not a major issue. My sources tell me that a huge percentage of the global automobile glass comes out of China and they produce for both the new car and aftermarket industry.

Windscreens sold in NZ must meet an international standard, I suspect your screen would be no different. There should be a marking on the screen to identify the standard it has been manufactured to.

Like everything that is mass produced there is always the potential for quality issues and this may be the case with the screen that is fitted to your vehicle. My research would suggest the distortion may be coming from the glass raw material and while unusual, is not uncommon within the industry. What I have also learnt is glass distortion can be very hard to pickup and is often a problem for some drivers and passengers and not others.

I have not been able to find any industry tests that would confirm whether the screen has a fault or not.

I can’t blame the glass company Manager for not wanting to replace the screen but he should take up your offer of testing the car at night in an effort to confirm the problem or not.

I think it is a matter of going back and expressing your concerns again. Often it’s the squeaky wheel that gets oiled in these cases.

If you are facing a brick wall ask for a technical representative to get involved from their Head Office.

At the end of the day if a fault does exist the glass company should replace the screen. I'm sure they will be able to claim back on the supplier.