Its kinda like when the shape of the cornea isnt normal so it cant focus light on the retina properly so vision is blurry 
as opposed to being short or long-sighted (the axial length of the eye being too long or short)
Its kinda like when the shape of the cornea isnt normal so it cant focus light on the retina properly so vision is blurry as opposed to being short or long-sighted (the axial length of the eye being too long or short)