Vision Defects and Eye Conditions

Astigmatism is caused by variation or disturbance in the shape of the cornea.

Presbyopia is caused due to the loss of flexibility of the lens.

In hypermetropia, the image is formed beyond the retina.

Glaucoma is a term describing a group of ocular (eye) disorders that result in optic nerve damage, often associated with increased fluid pressure in the eye.

A cataract is a clouding of the lens inside the eye which leads to a decrease in the vision. In cataract, the lens becomes opaque.

Ophthalmopathy due to thyrotoxicosis does not involve the uveal tract.

Schirmer's test involves a small piece of sterile filter paper placed well above the lower lid; failure to wet 10 mm of the paper in 5 min indicates defective tear production that may be due to keratoconjunctivitis.

This one is an incorrect statement as myopia usually begins in childhood and a child may have a higher risk if the parents are nearsighted. In most cases, nearsightedness stabilizes in early adulthood but sometimes it continues to progress with age.

During the dark adaptation of the human eye, its visual threshold minimises to a small fraction of its original value in the light. An analysis of the quantitative data signifying this adaptation shows that it follows the course of a bimolecular chemical reaction. It makes the rods functional. It takes some time for rhodopsin to be reformed. This is why, on entering a dark room at daytime or on coming out of a well-lit room at night, we feel blind for a while.

Hypermetropia (long-sightedness) occurs when the eyeball is too short or the cornea has too little curvature, causing light to focus behind the retina instead of on it. Convex lenses are converging lenses that add optical power to bring the focal point forward onto the retina, effectively correcting the vision defect. Concave lenses would worsen the condition by diverging light further, while cylindrical lenses correct astigmatism and bifocals address presbyopia.

The correct phrasing is done in option (1) in all the other options phrasing is done in an awkward manner.

Glaucoma is a group of eye conditions that damage the optic nerve, often due to increased pressure within the eye. Trachoma is an infectious eye disease caused by bacterium Chlamydia trachomatis and is a leading cause of preventable blindness worldwide. Both are specifically ocular diseases, not related to brain, skin, or kidney function.

Baldness is a hair loss condition, not a vision defect. Hypermetropia (farsightedness) and astigmatism (irregular cornea curvature) are genuine vision/eye defects. The question asks which is NOT a defect of vision - so baldness is correct.

Uveitis specifically refers to inflammation of the middle layer of the eye, termed the uvea but in common usage may refer to any inflammatory process involving the interior of the eye.

Myopia is the medical term for nearsightedness, a condition where close objects appear clear but distant objects appear blurry. This occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina instead of directly on it. Hyperopia (not listed) would be farsightedness.