According to somebody’s/something’s lights
Definition 1 of 1
Pro Tip 1/3Subjective Judgment
This phrase implies that an action or decision is based on someone's personal judgment or beliefs, which could be subjective and unique to them. 
She decorated the room according to her lights, and while some may find it eccentric, it was perfect for her.
Pro Tip 2/3No Absolute Truth
It suggests that what's right or appropriate might differ for each person, acknowledging that there isn't always one 'correct' way. 
He invested his money according to his lights, not following the usual advice.
Pro Tip 3/3Not Always Positive
The phrase can be neutral or slightly critical, suggesting that while actions are based on personal beliefs, they may not be wise or informed. 
According to his own lights, he chose to drop out of school, a decision others questioned.