The<unk>  is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the<unk>  refracts light, accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the<unk>  is approximately 43 dioptres. The<unk>  can be reshaped by surgical procedures such as LASIK. While the<unk>  contributes most of the eye's focusing power, its focus is fixed. Accommodation (the refocusing of light to better view near objects) is accomplished by changing the geometry of the lens. Medical terms related to the<unk>  often start with the prefix "kerat-" from the Greek word κέρας, horn.
Cornea
Apnea
Hyperpnea
Bronchospasm
Orthopnea
Tachypnea
Hypopnea
Cyclospasm