Of our five senses the eyes and our hearing are the two sense organs that provide us with the most information, from the world around us. Our eyes work by transmitting light through the cornea. The amount of light is governed by the muscles in the iris. The muscles control our focusing ability as well as controlling the pupil size which controls the amount of light passing through the eye. From here the light hits the retina which converts light images into nerve signals, these signals are then carried by the optic nerve to our brain. Quit a complex recipe to see and probably taken for granted by most of us. That is until we lose it.
Our hearing is not only our means of detecting sound it is also responsible for our sense of balance, letting our brain know which way up we are, to put it in a nut shell. The ear consists of three areas – these are the outer, middle and inner ear.
The canal runs from the outer ear to the middle ear and carries sound waves to our eardrum which acts as a divider between the outer canal and the middle ear. The middle ear itself is connected to the inner ear by three bones. Our cochlea receives sound which converts it to nerve impulses, these impulses are carried to the brain via the auditory nerve. Situated atop and to the left of the cochlea is the labyrinth which has three fluid filled canals (our sense of balance). Our head is the link that lets these fluid canals know which way up we are. When we move our head the fluid filled canals send impulses to our brain these impulses match up with signals sent by our eyes and limbs.
What Goes Wrong
The most common disorders that affect the eyes and ears are inflammation and infections. These disorders are often caused by infection, allergic reaction (usually viral, but sometimes bacterial). Conjunctivitis is one such disorder. The inflammation of the conjunctiva, which is a thin delicate membrane that covers the eyeball and lines the eyelid.
Conjunctivitis is an extremely common eye problem because the conjunctiva is continually exposed to micro organisms and environmental hazards that can cause infections or allergic reactions.
Other disorders of the eye could be cataracts which is a clouding of the eye lens and retinopathy a disease of the retina as well as dry eye syndrome, which covers a collection of conditions. Glaucoma is the name given to a group of conditions where by a build up of fluid within the eye builds up to a abnormal level and if left untreated could possibly cause irreversible nerve damage and blindness. These disorders could be caused by injury, diabetes, certain medication or for some other reason not mentioned here, and the good news is all are treatable.
The outer and middle ear are more prone to infection than the inner ear. However, that is not to say the inner ear never suffers from problems. One such problem that is more common than one would think is Mèniére’s disease.
Mèniére’s disease is a condition of the inner ear where disease may cause a build up of fluid in the inner ear this leads on to bouts of vertigo (spinning sensation) in the head, an extremely unpleasant sensation and possible noises in the ear which leads to gradual deafness.
Why Do They Use Drugs
Antibiotics would usually be prescribed to clear eye and ear infections. These drugs are usually safe and extremely effective in the treatment of bacterial disorders, ranging from from minor infections like conjunctivitis to life threatening diseases like meningitis.
Glaucoma is treated by a variety of drugs to reduce the fluid pressure mentioned earlier. These could include beta blockers and miotics to constrict the pupil, in other cases the pupil may need to be widened, this would be done with mydriatic drugs. Mydriatic drugs would cause the pupil to dilate, or widen.
The group of drugs that would cover such disorders covering this overview would be:
- Information on glaucoma.
- Medication that would be used to treat eye problems.
- Medication for ear disorders.