PARALYSIS OF ACCOMMODATION

(continue  ACCOMMODATION ANOMALIES)
Paralysis of accommodation also known as
cycloplegia refers to complete absence of accommodation.

Causes
1. Drug induced cycloplegia results due to the effect of atropine, homatropine or other parasympatholytic drugs.

2. Internal ophthalmoplegia (paralysis of ciliary muscle and sphincter pupillae) may result from neuritis associated with diphtheria, syphilis,
diabetes, alcoholism, cerebral or meningeal diseases.
 
3. Paralysis of accommodation as a 

Retina structure

Retina is developed from the two walls of the optic cup, namely: (a) nervous retina from the inner wall, and (b) pigment epithelium from the outer wall
.
 
(a) Nervous retina. The inner wall of the

FORMATION OF LENS VESICLE & OPTIC CUP

FORMATION OF LENS VESICLE

The optic vesicle grows laterally and comes in contact
with the surface ectoderm. The surface ectoderm,
overlying the optic vesicle becomes thickened to form
the lens placode (Fig. 1.6A) which sinks below the
surface and is converted into the lens vesicle (Figs.
1.6 B&C). It is soon separated from the surface
ectoderm at 33rd day of gestation (Fig. 1.6D). 

FORMATION OF OPTIC CUP
The optic vesicle is converted into a double-layered optic cup. It appears from Fig. 1.6 that this has
happened because the developing lens has invaginated itself into the optic vesicle. In fact conversion of the optic vesicle to the optic cup is due to differential growth of the