This time, they noticed a small black mark directly in the center of my father's eyeball.

这一次，他们看到一个小黑点正好在父亲的眼球中央。

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For the eyeball composed of membrane and liquid, the contrast of ultrasound imaging is not high due to its small variance in acoustic impedance.

对于由膜组织和液体构成的眼球来说，由于其超声阻抗差别不大造成眼超声成像的对比度不高。

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He measured the distance between the eyebrow and the hairline, and at the midpoint, in line with the right eyeball, he developed the brow: an enlargement, a small mound, almost as if something were beginning to grow.

NEWYORKER: The Limner