Eyes are door to the heart and mind. If we keep this door open to all the dirt and impurities, they would enter our mind and heart through our eyes and pollute them. A polluted mind would always fancy immoral (forbidden) acts and a polluted heart would insist us to act upon them.
[Surah Noor 24:30] **Command the Muslim men to keep their gaze low and to protect their private organs; that is much purer for them; indeed Allah is Aware of their deeds.
** We all know that "MEN" are aroused, but to say that it is impossible to control one's temptations without porn is actually blaming the ultimate Lord. Why would Allah (s.w.t) disallow something and not bless us with the capability and strength to avoid it ? This capability is developed through the teachings of the Prophet (saw) as I mentioned the hadiths in post # 95.