Ruling on prostrating when wearing glasses

There is nothing wrong with
praying when wearing coloured contact lenses or glasses, unless the glasses
prevent the worshipper from placing his nose or forehead firmly on the
ground when prostrating. In that case he has to take them off before he
prays or when he prostrates. 

Al-Bukhaari (812) and
Muslim (490) narrated that Ibn ‘Abbaas (may Allaah be pleased with him)
said: The Prophet (peace and blessings of Allaah be upon him) said: “I
have been commanded to prostrate on seven bones: the forehead” – and he
pointed to his nose – “the hands, the feet and the ends of the feet (i.e.,
toes)”  

Shaykh Ibn ‘Uthaymeen (may
Allaah have mercy on him) was asked about the person who wears large
glasses, which prevent him from being able to prostrate fully on the seven
parts of the body. 

He replied: 

If they prevent the end of
the nose from reaching the ground when prostrating that is not acceptable,
because what is carrying the face in this case is the glasses, which are not
at the end of the nose, rather they rest on the bridge of the nose. Based on
this, the prostration is not valid. The one who wears glasses that prevent
him from placing his nose in the place of prostration has to take them off
when prostrating. End quote from Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen
(13/186). 

And Allaah knows best.