corresponding to the axis of the eye, and at a point in which the
sense of vision is most perfect, is an oval yellowish spot, called after
its discoverer, the yellow spot or Macula lutea of Sommering.

Refracting Media.--The aqueous humor completely fills the anterior and
posterior chambers of the eyeball. The anterior chamber is the space
bounded in front by the cornea; behind by the front of the iris. The
posterior chamber is a narrow chink between the peripheral part of the
iris, the "suspensory ligament" of the lens and the "ciliary processes."

[348 MOTHERS' REMEDIES]

The vitreous body forms about four-fifths of the entire globe, It fills
the concavity of the retina and is hollowed in front, forming a deep
cavity, for the reception of the lens. It is perfectly transparent and of
the consistency of thin jelly. The fluid from the vitreous body resembles
nearly pure water. The crystalline lens enclosed in its capsule is
situated immediately behind the pupil, in front of the vitreous body. The
lens is a transparent, double-convex body. It is more convex on the
posterior than on the anterior surface. The rays of light go through this
body and converge to a point at the back of the retina.

BLEPHARITIS MARGINALIS.--This means a chronic inflammation of the margin
or edge of the eyelids accompanied by congestion, thickening and
ulceration of the parts and the formation of scales and crusts.

Causes.--The underlying cause is often an inflammation of the conjunctiva
where the proper care is not taken in cleansing the roots of the lashes
when the discharge collects.

Other causes are keeping late hours, smoke and dust.

Symptoms.--The red swelling along the roots of the lashes is often the
only symptom. This comes and goes at the least excuse, such as eye strain,
late hours, dust and wind. Scales and dust form in the severe forms, of
the disease. It is most common in children, extends over many years and
may finally result in the loss of the lashes, with the edge of the lid,
thickened, reddened and turned out.

Treatment.--This is tedious. Fit glasses if there is eye strain, reform
the mode of life and attend to any constitutional disease that may tend to
make it worse.

Local treatment.--Keep the parts thoroughly clean. The edges of the lids
should be washed carefully with soap and warm water or mild solution of
borax or soda until the crusts are all cleaned off and then use at night
an ointment composed of the fo