Segments are the two major parts of the eye separated by the posterior surface of posterior lens capsule and zonules. While the aquous humor is divided by the iris and pupil into two chambers.


Boundaries of Anterior Segment

Anterior boundary – posterior surface of the cornea. Some authors prefer to consider cornea as a part of anterior segment, in that case the anterior boundary of anterior segment would be the anterior surface of cornea. 

Posterior boundary – posterior surface of the posterior capsule of lens. The boundary continue above and below the lens along the posterior surface of the lens zonules and ciliary body.

Contents – aqueous humour, iris, lens (and cornea)


Boundaries of the Posterior Segment

Anterior boundary = posterior boundary of the anterior segment.

Posterior boundary – retina. According to some authors the posterior surface of sclera should be the posterior boundary.

Content – Vitreous humour, (retina, choroid, optic disk).



Boundaries of the Anterior Chamber

Anterior boundary – posterior surface of the cornea.

Posterior boundary – anterior surface of the iris and the plane of pupil.

Content – aqueous humour.


Boundaries of the Posterior Chamber

Anterior boundary – posterior surface of the iris and surface of pupil.

Posterior boundary – anterior surface of the lens anterior capsule and zonules.

Content – aqueous humour.



Image- Eye Segment and Chamber




  • “chamber” is a space filled with aqueous humour. They are parts of anterior segment.
  • segments are larger than chambers.

Try to remember the above image. Draw it two to three times. It would help your remember the differences.





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  • Anonymous Reply

    Thank you. Please make more such “memory aids”

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