The human diencephalon is composed of several regions. The thalamus which relays sensory information to the cerebrum, processes visual and auditory stimuli, and generates some emotions, among other functions.he human diencephalon is composed of several regions. The thalamus which relays sensory information to the cerebrum, processes visual and auditory stimuli, and generates some emotions, among other functions.
The LASIK surgery is performed by an ophthalmologist who uses a laser or microkeratome to reshape the eye's cornea in order to improve visual acuity. For most patients, LASIK provides a permanent alternative to eyeglasses or contact lenses.
More than 10 percent of LASIK patients in the U.S. require a second surgery, called âretreatment,â to restore the desired vision correction. This is more likely for people who were more nearsighted or farsighted, or had higher astigmatism before LASIK.