Dirty Glasses

My glasses were so
dirty I could not see
the world.

Patanjali, Yoga Sutra, Chapter One: Samadhipadah (the chapter on Samadhi):

1.1 Here begins the authoritative instruction on yoga.
1.2 Yoga is the ability to direct the mind exclusively toward an object and sustain that direction without any distractions [single-pointedness]
1.3 Then the ability to understand the object fully and correctly is apparent.
1.4 [When yoga is absent] The ability to understand the object is simply replaced by the mind’s conception of that object or by a total lack of comprehension.