Human eye and colorful world Flashcards
What is cornea?
Cornea is a thin membrane through which light enters the eye.
What is Retina?
Retina is a delicate membrane having light sensitive cells.
What is Iris?
Iris is a dark muscular diaphragm, which controls the size of the pupil.
What is the function of pupil?
The function of pupil is to control the amount of light entering the eye.
What is the function of optic nerve?
The function of optic nerve is send electrical signals to the brain.
What is power of accommodation?
The ability of eye lens to adjust its focal length is known as power of accommodation.
What do you mean by dispersion?
The splitting of white light into seven colors is known as dispersion.
Which light bent the least ?
Red light bends the least.
Which light bends the most?
Purple light bends the most.
What is myopia and how can it be corrected?
Myopia is also known as short sightedness. A person with this eye defect can only see near objects clearly compared to the far away objects. A person with this condition can be corrected by using a concave lens.
What is Hypermetropia and how can it be corrected?
Hypermetropia is also known as far sightedness. A person with this defect can only see objects at far distances clearly compared to near objects.This defect can be corrected by using a convex lens.
What is presbyopia and how can it be corrected?
Presbyopia is an age-related condition caused due to the weakening of ciliary muscles, hardening of eye lens and reduced lens flexibility. A person with this defect usually finds difficulty focusing on nearby objects and is unable to read or write.This type of people can be corrected by using a bifocal lens which consists of both concave and convex lens. The upper portion consists of concave lens which facility distant vision and the lower part consists of convex lens which facilitates near vision.
What is cataract and how can it be corrected?
Cataract is an age-related condition caused due to the loss of transparency of the lens by erosion of lens proteins. It usually results in blurry vision, cloudy lens and can be corrected by replacing the old lens with an artificial lens.
