Question

Structure of the Chamaeleon eye:

describe in detail important anatomical structures (including cells, tissues, and organs) of this sensory organ,

Answer 1

Structure of chameleon eye

The chameleon eye is the specialized structure consist of double eye chamber and have two eyes protruded out of the eye socket. Two eyes move independently and have bigger field of vision.Chameleon have field of vision of 342 degree, they can see the 180 degree horizontally and 90 degree vertically.They have unique eye lid membrane ,eye muscles,scleral cartilage and the lens.

a.Eye lid membrane

The eye lid membrane consists of the scales which is similar to the body scales of chamaeleon. The eyelids remains attached to the eyeballs and the aperture of the lens are open in front to visualize things.The scales of the eyelid can change the colour same like skin present at other part of the body.They have specialized nictating membrane named as third eye lid, it is made up of small cartilage and located at corner of the eye facing the nasal structure between eye lid and eye ball.This nictating membrane helps in protecting eyes anb.d keep them moist for proper functioning.

b.Eye muscles

The eye muscles are present under the eyelid and in the eye ball which helps in movement of eye during vision.The major eye muscles are - musculus rectus superior and inferior ,musculus rectus medialis ,musculus rectus lateralis and musculus obliquus superior and inferior.

Musculus rectus superior - It starts from the orbit on top of the eyeball to the front of the eyeball and end at the cornea base .It helps in movement of the cornea backdown.

Musculus rectus inferior - It starts from eye ball to the lower end of the cornea, it helps in the movement of cornea in the opposite direction compare to the musculus rectus superior i.e movement in downward middle direction.

Musculus rectus medialis and musculus rectus lateralis helps in movement of cornea in forward -midway direction and mid-backward direction respectively.

Musculus obliquus superior - It is present below to the musculus rectus superior ,over the eye ball .It helps in movement of eye ball downward and forward.

Musculus obliquus inferior -It is present at the lower side of the eyeball and helps in the movement of the eye in the upward direction.

c.Scleral cartilage

The scaleral cartilage establishes the cornea structure in the eye in the form of bony ring. The muscle fibers from the depressor muscles covers the surface of the scleral cartilage.

d.Lens of the Chameleon eye

The lens of chameleon eye is similar to the mammalian lens of the eye and it helps in refraction of light through the corneal muscles.The chameleon eye muscles contraction is controlled by the brain for the deformation of the lens in order to estimate the prey object distance.When eye muscle relaxed ,it doesn't refract the light and clumps it, that helps in the visualizing the object in large than normal retina.