While our vision looking outwards can easily be corrected, our vision looking inwards-- into our Self, our consciousness, our true nature-- takes more time and effort and sincerity to fix. This ignorance of the nature of the Self is the biggest blur of our internal vision. We mistakenly think the "self" thrives on strengthening the ego, seeing the "self" as important and others as less so. And we end up holding on to material and earthly gains and pleasures that we think benefit the "self", even as it hurts others. Because we create wars within ourselves, we think we have to be right, to be in control, to win, to be validated, to get what we desire, to be exempted from pain, to live forever, etc. Through this war within ourselves, our conflicts with others manifest. This is how we end up eating animals, enslaving humans for cheap labor, destroying nature, using genocide as an excuse for "cleansing", justifying killing for the "greater good". And because we are unable to see clearly, we suffer.
How then can we see inwards clearly and open the doorway to the true Self? It is through being an investigator of our own mind and consciousness. It is through experiencing that the individual self is not separate from others. This is why we practice asana, to keep the body strong and limber to be able to sit in meditation, and when we meditate we can do so for long periods without the aches and pains and discomforts of the physical body getting in the way, and we can go deeper and deeper inwards, until we find that boundary wherein the ego still lies, and we are so deep into the investigation that the boundary between the individual self and pure consciousness is broken down, and we open the doorway to our true identity.