Bhagavad Gita

ರಾಗದ್ವೇಷವಿಮುಕ್ತೈಸ್ತು ವಿಷಯಾನಿಂದ್ರಿಯೈಶ್ಚರನ್ ।
ಆತ್ಮವಶ್ಯೈರ್ವಿಧೇಯಾತ್ಮಾ ಪ್ರಸಾದಮಧಿಗಚ್ಛತಿ ॥೬೪॥
rāgadveṣavimuktaistu viṣayāniṃdriyaiścaran |
ātmavaśyairvidheyātmā prasādamadhigacchati ||64||

Gist of the sloka:
One who has overcome anger and revenge, keeping his senses under control, even if he is enjoying the senses will have his mind like crystal clear water.
It does not mean that one should shut his eye to the world and keep away from its activities. Rather the senses continually come back with various inputs. With the steady state of the mind, we should disregard such information and steel it with right knowledge. Practically, even if one has closed the eye, mind still wanders and would be reviewing the previous sights. One should avoid becoming the servant of the senses. This is the message given by Lord Krishna.
Do not get attached to the rewards by the senses, just experience it as it has come. Do not incur desires due to this experience. In this state, it does not matter what the senses come back from, for the mind with intellect does not give them the importance.
An example is, when we meet our friends in the street. We spend time talking about various things and each go on our own way. After sometime we meet another friend, who asks us what was the color of the shirt the first friend was wearing. We will not know and remember it. It is not that our eyes did not see it, just that the mind did not register it, as it was not important enough.
Similarly, if we train the mind to go behind only real truth, rest of the objects though visible to the senses will have no effect on our mind. At this stage, the senses are subordinate to the mind and not vice versa. Such a superior mind, if it picks on the right path will elevate our souls. The soul can then get into Dhyana state, understand the truth properly and would experience happiness. Soul will also get elevated.