The answer is D. Treatments decrease pain temporarily and must be repeated
Answer:
Common causes of blindness are diabetic neuropathy, glaucoma and cataracts.
Explanation:
Blindness refers to the complete lack of functional vision.It occurs when an inadequate amount of light hits the retina, or the information has not been delivered to the brain correctly.
Complete blindness : characterized by a complete and total loss of vision. Merck Manuals reports that legal blindness is defined as having equal to or worse than a 20/200 visual acuity in the better eye. Having a visual acuity of 20/200 means that someone with normal vision can see an object at 200 feet, and a person with impaired vision can see at a distance no further than 20 feet. Several different diseases can cause complete blindness; some develop later in life and some are present at birth. The leading cause of blindness in the United States is diabetes, according to the National Eye Institute. Diabetes causes diabetic retinopathy, which results in destruction of the retina. Other causes of complete blindness include age-related macular degeneration, which the National Eye Institute calls the most common cause of blindness in adults who are 60 or older; cataracts, which obstructs light from hitting the retina because of opaque patches on a lens; and glaucoma, which causes blindness due to damage to the optic nerve.
Color Blindness
:
People who have color blindness, also called dyschromatopsia, are unable to distinguish certain colors. This type of blindness more commonly affects men than women. Merck Manuals reports that the most common form of color blindness is red-green color blindness, which makes it difficult to distinguish certain shades of red and green. Color blindness is almost always present at birth, and is usually caused by the presence of a defective gene on the X chromosome. The reason that more men are affected by color blindness than women is that women have two X chromosomes; thus, even if they are "carriers" of a bad gene, their other X chromosome usually has a functional gene. Because men have only one X chromosome, the presence of one bad gene is sufficient to cause color blindness. Defective retinal cells result in some forms of color blindness; other forms are caused by defects in the optic nerve.
Night Blindness
:
Night blindness is vision impairment that occurs at night or when light is dim. It does not generally result in a complete lack of vision but significantly impaired vision. People with night blindness often have difficulty driving at night or seeing stars. Several different factors cause night blindness, according to the University of Maryland Medical Center. These factors include cataracts, birth defects, a vitamin A deficiency, or a retinal disease called retinitis pigmentosa
Answer:
The diagram presented is useful to understand the difference between these two types of exchange, which represents two fluid streams that travel parallel separated by a semipermeable or thermo-conductive membrane. The blue color represents the lowest value of the characteristic to be exchanged, while the red color indicates the highest value, so that the direction of the transfer will be of the fluid with the highest value to the lowest value. In the specific case of heat, the movement follows the second law of thermodynamics and in the case of solids as solutes the phenomenon of osmosis is followed. Exchange in equicorrent and countercurrent.
Direct flow
In this system the two fluids go in the same direction and their gradient varies along the flow path. Taking into account that the fluid present in the two tubes is the same, this method of exchange is only capable of exchanging half of the property (heat, matter, concentration, etc.) between fluids, no matter how long the flow path If either of the two currents changes their property by 50% or more, the exchange will be interrupted since the gradient is reduced to zero, indicating that the equilibrium point has been reached. In case of having unequal flows, the equilibrium conditions will be a little closer to the conditions of the current that has the greatest flow.
25:100, 100:400, 2:8, etc
