Glasses fit in without any problems, also iPhone 8 or SE 2nd gen, it would be tight with an iPhone 11, even without the inner shell.
Size of tray = approx. 16x9x5 cm (LxWxH, corners rounded), the basket is approx. 15x8 cm with rounded corners.

Clean each item at least 2 times!

The bottom surface is slightly smaller, about 15 x 8 cm, than the upper opening of the tray. But since the "corners" are very rounded, my mobile phone of 14 x 7 cm only just fits in the tub in a slanted position, but not in the basket. It's OK with my glasses.