Advantages of contact lenses are all except
High-Yield Explanation
Ans. is `d' i.e., Improved corneal oxygen supply Advantages of contact lens Contact lens has several advantages over spectacles :- Retain binocularity in Anisometropia owing to less magnification of size of retinal image. Irregular astigmatism can be corrected. No peripheral distoration as it moves with eye and there is normal field of vision. Not subjected to moistening. Several varieties of contact lens can aid in treatment of dry eye. Hard contact lens may stimulate reflex tearing and also prevent evaporation of tear . Cosmatically superior. Tinted contact lenses relieve photophobia in albinism. Disadvantages of contact lens Complications of contact lens wearing are : ? Intolerance : - Some people find wearing contact lenses intolerable. Corneal complications : - Corneal abrasion, Corneal edema, Corneal vascularization, Microbial keratitis (Pseudomonas, acanthamoeba), Sterile corneal infiltrate. Giant papillary conjunctivitis. Hypoxia : - Cornea is deprived of oxygen from the tear film by the presence of the contact lens. The cornea becomes edematous and new vessels may develop in the limbal area. Sensitivity : - This may develop in response to the preservative (thiomersal) in the cleaning and soaking solution. This results in allergic conjunctivitis.