Fig. 11.
"The strabismus-hook."
Fig. 12.
"The iris forceps." The blunt points (a and b) of the blades of the forceps should remain in contact with each other when pressure is made to bring those portions of the surfaces in contact, which extend from the points to within a quarter of an inch from them.
Iris forceps are made with blades of varying degrees of curvature; the surfaces near the points may be roughened or smooth; or the points may be toothed.
The points of the forceps used for fixing the eyeball during operation should be toothed. Each tooth should be sharp, and almost in a line with the blade, if the forceps are used for grasping the sclerotic.
Fig. 13.
"The compressorium forceps." The solid blade (a) has to be passed beneath the eyelid (upon the conjunctiva), and the blade (b) upon the skin of the eyelid. The screw (c) serves to maintain pressure of the blades against each other.
Fig. 14.
"The stop speculum." This instrument is used for keeping the eye-lids open. The spring of the wires of the speculum can be regulated by the screw (a).
A very light stop speculum, made of thin wire, is employed during extraction of cataract, and during operations on glaucomatous eyes.
PLATE V.
Fig. l.
The optic disc and the immediately adjoining retina, choroid, and sclerotic, of the healthy left eye of a person aged 20, with blue irides.
The round optic disc is represented near the centre of the figure. At its outer and inner margin it is skirted by a crescentic patch of brown
