How to check health of optical drive?

[Sinizter]

When burning discs with Nero Essentials, when I have verify data after burning option on, the discs shows up with quite a few sectors bad.

Before this they were always fine. All discs were from one tub, which I just bought from Staples. 16x Verbatim burned at 8x and 6x, but still showing errors.

I have another tub of the same stuff bought elsewhere a long time back, and they were burning without errors before.

I am concerned that it may be my drive failing. How can I confirm whether I got a duff tub of discs or if its my drive?

[FatalSaviour]

With some disc tools, (I'm not sure whether the Nero bundle still covers it) you can check the dye used in the discs I believe.

It may be worth comparing the two, to see if the dye has changed?