What are the importance of the cataracts in Egypt?
The cataract system created a natural boundary at Aswan, separating Egypt from its southern neighbor, Nubia.
What is the first cataract in Egypt?
The Nile River is shown above passing the granite islands that form the first cataract at Aswan City, Egypt. Cataracts occur where outcrops of granite, as well as other resistant rocks, reach the banks of the Nile River.
What is cataract of a river?
cataract, a waterfall (q.v.), especially one containing great volumes of water rushing over a precipice. Rhine Falls. Rhine Falls, on the upper Rhine River near Schaffhausen, Switzerland. Phter.
How did cataracts affect Egypt and Nubia?
How did the cataracts of the Nile affect Nubian trade? The cataracts prevented Nubians from trading by traveling on the river, so Nubian trade routes had to be over land.
What is the difference between a cataract and a waterfall?
A cataract is a type of waterfall with a large, single vertical drop, usually falling clear of the bedrock. A cascade waterfall is used to describe a waterfall running over an irregular steep surfaced gradient where the water is generally in contact with the river bedrock.
Why is a waterfall called a cataract?
The term “cataract” is derived from the Latin, “cataracta” which means “waterfall” and the Greek” katarhaktes” which means “waterfall, broken water; swooping, rushing down”.
What are cataracts caused by?
Most cataracts develop when aging or injury changes the tissue that makes up the eye's lens. Proteins and fibers in the lens begin to break down, causing vision to become hazy or cloudy. Some inherited genetic disorders that cause other health problems can increase your risk of cataracts.
How did the cataracts of the Nile river affected Nubian trade?
How did the cataracts of the Nile affect Nubian trade? The cataracts prevented Nubians from trading by traveling on the river, so Nubian trade routes had to be over land.
What is an example of a cataract?
For people who have cataracts, seeing through cloudy lenses is a bit like looking through a frosty or fogged-up window. Clouded vision caused by cataracts can make it more difficult to read, drive a car (especially at night) or see the expression on a friend's face.
What does cataract mean in Latin?
"Cataract" is derived from the Latin cataracta, meaning "waterfall", and from the Ancient Greek καταρράκτης (katarrhaktēs), "down-rushing", from καταράσσω (katarassō) meaning "to dash down" (from kata-, "down"; arassein, "to strike, dash").
What does a cataract look like?
Clouded, Spotty, and Double Vision Like we previously stated, a cataract is characterized by cloudy eyes and vision. Because of the cloudiness cataracts cast over the lens of people's eyes, looking through an eye lens that is diseased with cataracts may seem like looking through a fog.
What’s pink eye caused from?
Most cases of pink eye are typically caused by adenovirus but can also be caused by herpes simplex virus, varicella-zoster virus, and various other viruses, including the virus that causes coronavirus disease 2019 (COVID-19).
What are the 3 types of cataracts?
There are three primary types of cataracts: nuclear sclerotic, cortical and posterior subcapsular.
- Nuclear Sclerotic Cataracts. …
- Cortical Cataracts. …
- Posterior Subcapsular Cataracts.
What is a cataract made of?
A cataract occurs when there is a buildup of proteins in the lens, creating protein clumps. These clumps, or deposits, prevent light from passing clearly through the lens, thus disrupting normal vision. There are several reasons why a cataract may form including: Aging – The eyes mainly consist of water and protein.
How did cataract Falls get its name?
An older expression for the same condition was web in the eye, so the name was most likely derived from the barred structure of the portcullis or window grating, rather than as a physical barrier. It sounds improbable, but nobody seems to have come up with a better explanation.
What are the 5 types of cataract?
There are 5 main types of cataracts.
- Age-related cataract. As you age, a cataract can develop because of natural changes in the lens of your eye. …
- Traumatic cataract. Serious eye injuries can damage your lens and cause a cataract. …
- Radiation cataract. Certain types of radiation can cause cataracts. …
- Pediatric cataract.
Aug 3, 2019
Can a fart cause pink eye?
This is a popular myth amongst school-age pranksters that asserts a person who uses a pillowcase that a practical joker farted on will later contract pink eye. You cannot get pink eye from a fart. Flatulence is primarily methane gas and does not contain bacteria. Additionally, bacteria die quickly outside the body.
Is pink eye from poop?
You CAN get pink eye from poop Poop — or more specifically, the bacteria or viruses in poop — can cause pink eye. According to the Centers for Disease Control and Prevention (CDC) , if your hands contain fecal matter and you touch your eyes, you can get pink eye.
What is black cataract?
Black cataract is very specific. The lens nucleus has become so hardened, sclerotic and blackened that it has gone beyond what is known as brunescence. Brunescence is a discoloration of the nucleus that occurs as the nucleus becomes sclerotic. Brunescence begins as a yellowing and progresses to orange and brown.
What is a cataract geography?
(ˈkætəˌrækt) n. 1. ( Physical Geography) a large waterfall or rapids.
What is the difference between a waterfall and a cataract?
Horsetail: Descending water maintains some contact with bedrock. Cataract: A large, powerful waterfall. Multi-step: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool. Block: Water descends from a relatively wide stream or river.
Is cataract another word for waterfall?
Cataract synonyms (Figuratively) A waterfall-like outpouring.
What is the rarest cataract?
Christmas Tree or Polychromatic Cataract This rare type of cataract refers to the appearance of colourful, iridescent crystals that form within the lens.
Can u get pink eye from sperm?
You can get conjunctivitis (pink eye) from some bacteria in semen. This includes STI bacteria, such as chlamydia, gonorrhea, and syphilis. Common symptoms include: eyelid swelling.
What happens if you fart on a pillow?
This is a popular myth amongst school-age pranksters that asserts a person who uses a pillowcase that a practical joker farted on will later contract pink eye. You cannot get pink eye from a fart. Flatulence is primarily methane gas and does not contain bacteria. Additionally, bacteria die quickly outside the body.
Can you get pink eye from sperm?
You can get conjunctivitis (pink eye) from some bacteria in semen. This includes STI bacteria, such as chlamydia, gonorrhea, and syphilis. Common symptoms include: eyelid swelling.
Why do we have eye boogers?
When you blink, tears move across the surface of your eyes to keep them clean. But when you sleep, you don't blink. The mucus and debris that's normally washed away by tears when you blink starts to collect in the corners of your eyes. This causes you to wake up with eye boogers.
What is a white cataract?
These cortical spokes can spread to adjacent fibers and cover the whole of the capsule, in which case the cataract is classified as mature/intumescent cortical cataract. In these cases, the entire cortex from the nucleus to the capsule adopts a white color.
What is brown cataract?
A brunescent, or brown, cataract is often correlated with the maturity of a cataract and can cause decreased visual acuity. Brunescent cataracts can cause poor contrast and color discrimination, especially at the blue end of the visible light spectrum.
Why is a cataract called a cataract?
Cataract dates to the 14th century and comes from the Latin word cataracta, meaning "portcullis." The Latin pertains to the ocular cataract, probably because it obstructs one's vision much like the portcullis's heavy iron grating obstructs passage into a fortress or castle.