centration point

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When the patient has constant esotropia, a centration point should he investigated. This is a point inside the conventional 40 cm near fixation distance at which the visual axes can be observed to coincide. If this occurs at 10 cm, there will be no movement on the cover test at this distance and the patient is effectively nonstrabismic at that point in space. This provides a functional position in space at which to begin VT.文中的“centration point"的中文名词是什么？