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From the Archives of the Archives |

A look at the past . . .

Arch Ophthalmol. 2009;127(6):736. doi:10.1001/archophthalmol.2009.116.
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Extract

In the extraction of senile cataract by the flap operation downward, it occasionally happens that an unintentional innervation of the ocular muscles, immediately after the section is completed, forces the lens, with its capsule unruptured, out of the eye. The lens then ordinarily preserves its senile, flattened form, but at times I have observed that with liquefaction of the cortex the extruded lens in its intact capsule exhibits the round form which is found post mortem in the eyes of the young. Since the liquefied cortex can have no particular elasticity, this fact can be explained only as being due to the elasticity of the lens capsule, and it is also conceivable that an elastic membrane filled with soft contents should naturally take on a spherical shape when this is not prevented by a counter-traction. The greater thickness of the anterior capsule thus explains also its greater curvature in accommodation. The evident change in the form of the lens in accommodation is usually explained as being due to the effort of the lens substance to assume a spherical shape. This view, doubtless, proceeds from the idea of the “musculus crystallinus,” held by the older anatomists (Loewenhoek, Pemberton, and also Thomas Young), yet I believe, on the ground of the preceding observation, that the elasticity of the lens capsule alone is sufficient to produce the change in shape, while the lens proper plays a more passive role.

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