Anatomy of the bony orbit:

The major bones forming the orbit are:

• Maxilla forms the bottom/floor (green)
• Frontal forms the top/roof (blue)
• Ethmoid forms part of the medial wall (grey)

The orbital cavity itself is a conical shape, narrowing posteriorly.

The medial walls of the orbits (the inner sides closest to the nose) are parallel to each other and are aligned with the sagittal plane (the vertical plane that divides the body into left and right halves).

The lateral walls (outer sides of the orbit, closer to the temples) angle outward from front to back. So, instead of being parallel like the medial walls, they spread apart — forming a wider angle between them. This is what gives the orbit its conical shape.

Other important structures in the bony orbit are:

• the optic canal-carries optic nerve and ophthalmic artery
• the superior orbital fissure which is found lateral to the optic canal- transmits other structures from the cranial cavity into the orbit
• the nasolacrimal duct which is found on the medial side of the orbit anteriorly and travels downwards to the nasal cavity

Surface anatomy:

Internal anatomy:

The eyeball contains three layers of tissue, the fibrous tunic, the vascular tunic and the nervous tunic.

The fibrous tunic is the outermost layer and consists of the sclera (the white part of the eye) and the cornea (transparent bubble on the center of the front of the eye)- the one is basically continuous with the other.

• Conjunctiva - transparent, with blood vessels-covers the sclera, dilates when eye is irritated or inflamed