Collimated visual display apparatus comprising an aspheric screen (12) and a curved collimating mirror (16), characterised in that the aspheric screen (12) is not a surface of revolution about an axis, the aspheric screen (12) comprises first and second parts (6, 8) which are separated from each other by a third part (10), the first and second parts (6, 8) are curved in cross section and if connected together then they would form a surface of revolution, the third part (10) is straight in cross sectional view and is a short cylindrical centre section, and the collimated visual display apparatus is such that the aspheric screen (12) has an outer curved surface that is viewed via the curved collimating mirror (16) by a user of the collimated visual display apparatus.