Emmetropia rest from infinity parallel to the light emitted by the object's refractive eye focus on the retina to form, it is far from clear to see, and spread out near the light emitted by the object is bound to end like with the cheap oakley sunglasses retina, then see unclear; the human eye is by changing the curvature of the lens to increase the eye's refractive power to close the object image on the retina can still achieve that vision, the eye such as the regulation mechanism of action.

  1 adjustment mechanism

   Participate in regulation of the organization are: the lens. Ciliary muscle. Suspensory ligament. Abnormal relationship between the three close, when the ciliary muscle at rest, the suspensory ligament tension, flat lens, refractive power weakened, this is adjustable stop, again, he said the eye of the rest; but ciliary muscle contraction, the ciliary processes reduced the formation of the ring , suspensory ligament laxity, cheap oakleys lens then citizenship becomes convex to its inherent flexibility, strengthen its refractive power, namely, the state regulation of the eye.

 (2) and adjust the power adjustment range. Adjustable rate: (1) adjust the far point: In optics, the corresponding object point and image point is called the conjugate focus. When adjusting the rest, and macular phase conjugate axis is referred to as adjustable as far point. (2) adjust the near point: When the eye can see the power of regulating the use of all eyes last point. (3) Range: far point and near point of adjustment between the use of any distance can reach out as the regulator, this range is called adjustment fake oakley sunglasses range. (4) adjust the force: regulatory role, because of changes in lens refractive power generated to be expressed in units of diopters. Adjust the force (D) = 1 / adjust the distance (m) (5) adjustment range: looking far point and near point of watching the difference between the refractive power is called amplitude (also called absolute adjustment force, maximum force adjustment) adjustment range (D ) = 1 / near-point distance (m) -1 / far distance (m) adjustable rate (D) = near point of the refractive power of the gaze + (± refractive error degrees) (b) the collection of role when myopia near objects, in addition to regulation, the eyes also must turn inward, so that the visual axis to being objects, this effect is called a collection. In the regulation of the collection is also associated with miosis. Three are in the oculomotor control completion. Look at the past simultaneous adjustment. Miosis and a collection of nearly three phenomena known as the triple fake oakleys reflex movement. 1 set of objects near point when looking closer, the two degree increase in transfer, but there are certain limits, the limit occurs when the object and then close diplopia. In the absence of diplopia occurred recently when a collection point for the near point. 2 sets of the strength of the collection angle to angle meter (Ma), said that when two objects look in front 1m distance, its collection force of 1 meter angle. M size of the angle from the size of the pupil due to each different.