Sometimes we need help to see things for what they really are.  New information or a different vantage point can shed light on people and events.  They are eye openers.
The Psalmist tells us that God’s law is an eye opener.  The commandment of the LORD is pure, enlightening the eyes.”  (Ps. 19:8b; ESV)  We don’t usually think of the law in these terms.  The law is a set of rules or directions.  Or, the law is the standard by which God measures our righteousness or unrighteousness.  But an eye opener? Yes, the law opens our eyes to God’s love for us.
To get at the Psalmist’s meaning, let’s draw a parallel between Natural Law and Moral Law (granting that the Psalmist himself would never have drawn an analogy like this).  
Knowing the laws of nature helps us to see the ordinary events around as a function of rational principles.  What might look like utter chaos to an untrained eye is the expression of a complex order for someone who knows Chaos Theory.
Physics, Meteorology, and Seismology allow us to predict the future course of planets, next week’s weather, and even impending earthquakes.  Our knowledge of Natural Law opens our eyes to the patterns of nature and sometimes helps us to live more securely and effectively on this planet.  
We can launch spacecraft to distant planets and land probes on them to gather data.  Hurricanes pose an enormous threat but weather forecasts can warn us to get out of their path.  Tsunami warning systems at least provide the promise of minimizing the human destruction of tidal waves.
By analogy, the Moral Law opens our eyes to our relationship with God and our relationship with each other.  But here is where the analogy ends.  Natural Laws tell us how things will be.  Moral Law tells us how things ought to be.  Each kind of law sheds light on our lives.  They are eye openers.  But Moral Law helps us to see the course that human freedom has charted.

Take for example the Ten Commandments.  
The Second Commandment forbids idol worship.  (Exodus 20:4)  Imagine a world in which no one prized money, power or sex above God.  Financial markets would never collapse because of greed.  Political leaders would pursue the common good instead of securing their position.  There would be no such thing as international sex trafficking.
The murder rate would be zero.  No one would need alarm systems on their car or in their home (okay, maybe not great news for security companies).  Cyber bullying (an especially vicious form of bearing false witness made possible by our technology) would have never been heard of.
I could go on, but I’m sure you get the point.  The Moral Law gives us a vision of the Kingdom of Heaven.  And that vision reminds us again and again how far short of the glory of God we humans have fallen.  
We are rightly motivated by that vision to strive for personal righteousness and social justice.  And we can indeed make some improvements.  But no matter how far we come, the law will remind us that we have fallen short.  If all we have is the law, our motivation to live up to the law will slowly wither away or devolve into hypocrisy. 
But we are not left with the law alone.  We live under the Cross of Christ.  St. Paul puts it this way: “not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith.”  (Philippians 3:9; ESV)
Our sins were imputed or attributed to Christ on the Cross so that his death atones for them once and for all.  But more than this, Jesus lived a perfectly righteous life.  And that righteousness is imputed or attributed to us.  In other words, the Cross is the ultimate eye opener.
God the Father sees us through the Cross and sees us once and for all through his Son.  And we see ourselves as God see us, as sinners redeemed by Christ.  The Law is fulfilled in us through Christ.
We have nothing left to prove, nothing to be ashamed of, nothing to regret.  We are infinitely loved and infinitely valuable.  We never have to justify ourselves again.   The Cross is the light that opens our eyes to God’s love for us.
(The image above is Joao Zeferino’s Moses Receiving the Tablets of the Law.)