Indriya-saṃvara: Guarding the sense doors
Watchfulness at the gates where sight, sound, and the rest come in. Your eye is one of those gates, and propped open it lets in the very sight that trips your foot and leads the rest of you after it. Guarding it means catching the grab before a drifting shape turns into a hook you swallow. Keep that gate like a door held shut against blowing dust, and the eye stops being the thing that makes you fall.
Taṇhā: Craving
This thirst reaches out and grabs whatever the senses set in front of it. Your eye alone never made you stumble; the thirst riding in behind the glance is what closes the hand. Pluck out the eye and leave that thirst breathing, and the ear or the hand will trip you by morning, since the wanting simply moves to the next open door. The cut aimed at the eye works only when it reaches the wanting behind it, the way you only kill a weed by pulling out the root.
Ādīnava: The peril inside pleasure
Danger hides inside the thing that pleases you. The eye is sweet, and that sweetness is the trouble, since the same glance that delights you is the road that ends in fire. Seeing this is why your hand goes to the eye at all: you have looked past the bait and noticed the hook. Once the fire waiting at the end of the pleasant look is plain, plucking the eye stops sounding mad and starts sounding like plain care for your life, the smallest price for staying out of the flames.
Saṃvega: Urgency
The jolt that lands the moment the stakes come clear. Two eyes carried whole into the Gehenna of fire, set against one eye and life: that arithmetic is built to knock the breath out of you. The shock is the point, since a mild alarm you keep meaning to answer never gets you out of a burning house. Let the fire press that close, and your hand moves today rather than in a someday that keeps not arriving.
Nekkhamma: Letting go
Setting down what binds you and walking on lighter. Pluck it out, and cast it from you: here is the open hand at its most severe, releasing not a coin but the eye itself. The casting away looks like pure loss, yet in the same breath comes the reward: the one-eyed and maimed are the ones who walk on into life. You loosen your grip on the smaller thing so the whole of you is not dragged off, the way a swimmer lets a heavy bag sink to reach the surface.