The principles and practice of ophthalmic surgery : comprising the anatomy, physiology and pathology of the eye, with the treatment of its diseases / by Benjamin Travers and Joseph Henry Green, edited by Alexander Cooper Lee.

  • Travers, Benjamin.
Date:
MDCCCXXXIX [1839]
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of ophthalmic surgery : comprising the anatomy, physiology and pathology of the eye, with the treatment of its diseases / by Benjamin Travers and Joseph Henry Green, edited by Alexander Cooper Lee. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    THE LACHUYMAI. SAC. 9 each other, leaves a groove, or sulcus, between the Mei- bomian borders and the surface of tlie globe, when the cihary borders are in contact. This increases in breadth toward the nasal angles of the tarsi, where the puiicta, or orifices of the lachrymal excretories, are placed upon two small eminences accurately opposed, and terminating the :\Ieibomiau borders ; they are two pinholes formed in the cartilaginous substance, and thus preserved per- manently open. LACHEYMAL DUCTS. The lachrymal ducts extend from the puncta to the lachrymal sac ; the superior is longer and more curved than the inferior ; the former is concave inferiorly ; the latter is nearly straight, a little concave upwards ; they both open into the external part of the sac, a little above its middle, sometimes by one, and sometimes by distinct orifices, behind the tendo ocelli; each duct is surrounded by a process of that tendon, and lined by mucous mem- brane. LACHRY.MAL SAC. The lachrymal sac is a small oval pouch of mucous membrane, closed above, and leading below into the na- sal duct; it is situated in a fossa formed by the anterior concave portion of the os unguis, and the nasal process of the superior maxillary bone on which it rests ; in front it i.s covered by the skin, the tendo oculi, some fleshy fibres of the orbiailaris, and a strong fascia which is de- rived (rtrm the tendon, and connected to the surrounding l^ny margin. On its ou^cr side there is an opening for