Final answer:
The correct spelling for the eye's focusing ability is 'Accommodation.' It is a vital process involving the parasympathetic control of the eye's lens to focus on near and distant objects. Proper functioning of this ability is crucial for clear vision and changes with age, sometimes requiring corrective lenses.
Step-by-step explanation:
The correct spelling for the focusing ability of the eye is B) Accommodation. This term refers to the eye's ability to adjust its focal length, which allows us to focus on objects at different distances. The process involves altering the shape of the eye's lens, controlled by the parasympathetic fibers of the oculomotor nerve. Notably, the accommodation-convergence reflex is a coordinated effort that pairs the convergence of the eyes with the adjustments by the ciliary muscles for the purpose of maintaining clear vision when looking at close objects.
As people age, their ability to accommodate may decrease, a condition known as presbyopia, often requiring corrective lenses. The science behind how the eye adjusts its focal power and the corrective measures for common refractive errors are fundamental concepts in understanding vision and eye health.