Sheikh Muhammad al-Habadan said showing both eyes encouraged women to use eye make-up to look seductive.
The question of how much of her face a woman should cover is a controversial topic in many Muslim societies.
The niqab is more common in Saudi Arabia and the Gulf, but women in much of the Muslim Middle East wear a headscarf which covers only their hair.
Sheikh Habadan, an ultra-conservative cleric who is said to have wide influence among religious Saudis, was answering questions on the Muslim satellite channel al-Majd.