स यत्रायमात्माबल्यं न्येत्य संमोह- मिव न्येत्यथैनमेते प्राणा अभिसमायन्ति स एतास्तेजोमात्राः समभ्याददानो हृद- यमेवान्ववक्रामति स यत्रैष चाक्षुषः पु- रुषः पराङ्पर्यावर्ततेऽथारूपज्ञो भवति ॥
In plain words
There comes a point where this self sinks into weakness, and seems to slip into confusion. That is when every one of your faculties gathers around it, and, taking its light with it, it withdraws down into the heart alone. And when the part of you that sees through the eye finally turns away, you stop knowing shapes at all.
Close to the Sanskrit
That, when this self, having gone to feebleness, having gone as if to confusion — then these vital breaths gather around it; taking up with itself these particles of light, it descends into the heart alone. When this person connected with the eye turns backward, then it becomes one that does not know form.