Human Eye Flashcards
What is the cornea?
It is a colourless and transparent so that light can enter the eye
What is the pupil?
The pupil is like a “window” that lets light enter the lens
What is the iris?
The iris controls the pupils size, it is a ring of muscle that contracts and relaxes automatically to regulate amount of light through eye
What are the ciliary muscles?
They hold up the lens in place behind the pupil, which are attached to the lens by thin ligaments
What is the retina?
The retina produces the image for the eye
What are rods?
Rods are sensitive to light and people have about 120 million
What are cones?
Comes are sensitive to colours and people have about 6 million of them
What is the optic nerve?
Nerve signals are sent through the optic nerve to the brain to interpret
What is the blind spot?
The are where the optic nerve and blood vessels connect to the retina, there are no cones or rods
What is normal vision?
It is referred to as 6/6 vision
What is refractive vision problems?
An inability of the eye to focus an image properly on the retina
What is myopia?
You can see things near but not focus on distant objects
What is hyperopia?
You can see distant objects clearly, but has difficulty focusing on objects that are close up
What is astigmatism?
The cornea has an irregular curvature
What is presbyopia?
An age related vision defect hen the lens and cornea lose some of their elasticity and can’t shape as easily
