Where Islam has adorned women with Hijab, it has also ordered men to lower their gaze.
Lewd gaze (badnazari) a poisonous arrow of Satan
Satan is the eternal enemy of mankind. He employs various tricks to drag human beings down into the abyss of humiliation. One among them is evil gaze. When a human being gets caught in this trap of evil gaze, he falls into the trap of Satan. Then, the paths to other sins become easy for that person. When a person controls the desire of his/her Nafs (the base self), he is honored with the sweetness of Iman. As the Holy Prophet (Sallallahu alaihi wa sallam) said:
Translation of Hadith: It has been narrated on the authority of Hadhrat Abdullah bin Mas'ud (May Allah Ta'ala be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) said: Gaze is one of the poisonous arrows from the arrows of. Whoever abandons lewd gazing out of my fear, I will reward him for that with the perfection of Iman, the sweetness of which he (or she) will feel in his (or her) heart.
Prohibition of Describing the Beauty of a Non-Mahram Lady
It is prohibited to see a non-Mahram woman as because of this a man’s heart starts leaning towards the non-Mahram woman. In this there is a very strong possibility of trouble. In the same way, when a woman speaks about the beauty of a non-Mahram woman in front of her husband and describes the beauty of that lady, the man starts imagining her. Here also, there is a chance of trouble, the way there is in seeing directly with one's eyes.
That’s why the Holy Prophet (Sallallahu alaihi wa sallam) has prohibited women from meeting such a woman who mentions their beauty before her own husband.
Translation of Hadith: It has been narrated on the authority of Abdullah bin Mas'ud (May Allah Ta'ala be well pleased with him) that he heard that the Holy Prophet (Sallallahu alaihi wa sallam) say: No woman should meet another woman with the intention that she mention (the other lady's) beauty before her own husband in such a detailed manner as if he is watching her.
Refraining From Lewd Glances and the Sweetness of Worship
When a Muslim man refrains himself from lewd gazing, whenever his gaze falls on any non-Mahram, he turns it away, then from the Court of Allah Ta'ala, he is given sweetness in worship, as the Holy Prophet (Sallallahu alaihi wa sallam) says:
Translation of Hadith: It has been narrated on the authority of Hadhrat Abu Umama (May Allah Ta'ala be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) said that whichever Muslim unintentionally sees the beauty of a non-Mahram woman and immediately turns his gaze down , then Almighty Allah will grant him the guidance to perform such worship, the sweetness of which he will actually feel.