What is the cause of farsightedness? the cornea is irregular. the cornea is opaque. the eyeball is shortened. the eyeball is elongated.

The eyeball is shortened.

Explanation:

Farsightedness, popularly known as difficulty seeing closely, is a common refractive problem, where the image in the eye forms after the retina rather than exactly over the retina, which hinders the brain's ability to process the image correctly. In farsightedness there is no difficulty in seeing objects from afar, but when you get closer, it becomes very difficult to focus on them.

The eyeball works the same way as a dark box: light enters the pupil and forms the image on the retina. The shape of the eye and cornea is perfect for the image to form in the right place (the macula), and then the information is sent to the brain by the optic nerve.

When you have farsightedness, the eyeball is a little shortened or the flatter cornea, so the image ends up forming after the retina, ie the image the retina captures is not correct.

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).