KERALA PSC / CDPO / BIOLOGY / SOME OF THE EYE DEFECTS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

 

KERALA PSC / CDPO / BIOLOGY / SOME OF THE EYE DEFECTS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CDPO / BIOLOGY / SOME OF THE EYE DEFECTS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

Myopia: Also known as near sightness or short sightness. Near object is clear. Far object is not clear Eyeball become longer. Image is formed in front of Retina. Can be remedied by concave lens.

Hypermetropia: Also known as long sightness or far sightness. Far object is clear, near object is not clear. Eye ball become short. Image is formed behind the Retina. Can be remedied by convex lens

Astigmatism: Curvature of cornea become irregular and image is not clearly formed. Remedied by cylindrical lens

Glaucoma: It is an eye ailment that causes increased pressure within the eye ball which puts pressure on the optic nerve. If the pressure is higher than a certain level and not controlled, then it may lead to blindness.

Trachoma: It is increased in Redness of eye and more secretion of watery fluid. It is due to infection of bacteria, Chlamidia trachamastis. Due to these follicles may form in conjunctiva.

Xerophthalmia: It is due to deficiency of Vitamin A(A₂). During this conjunctiva or cornea becomes keratinized. It may lead to blindness.

Strabimus: In this type eyeball remain in somewhat bent position which is due to long ocular muscles formed during development of eye. Operation is needed at early stage. Also associated with squint.

Presbiopia: During this power of accommodation of lens decreases due to age factor and defected metabolism. Also known as age sightness. Can be removed by bifocal lens.

Photofobia: No clear image in bright light

Emmetropia: Normal vision

Cataract: It is the condition where lens became opaque which is due to defective protein metabolism leading to blindness. It may be due to disease or old age. It is remedied by replacing lens.

Colour blindness: It is known as daltonism. It is the inability to distinguish between red and green colour. It is a sex linked (x-linked) genetic disorder.

Night blindness: During this Rhodopsin is not resynthesized while it is regenerated in dim light.

KERALA PSC / CDPO / BIOLOGY / SOME OF THE EYE DEFECTS / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY