Taken from Passport Office guidance to photographers
Customers who wear glasses should remove them to ensure that an accurate biometric can be obtained. Glasses can often show reflection or glare from flash, and the frames can obscure facial features. While this may mean that their passport photo does not show them as they usually appear, their photo will still be a good likeness.
Customers with a visual impairment should also follow this guidance. Dark, tinted or mirrored glasses must be removed - otherwise a biometric cannot be captured.
https://www.gov.uk/government/public...-photographers