By: Aglaheth Zaragoza
There is something about the eyes that just make them so captivating. The color or eye shape really seems to draw attention. Even more so on a brilliant sunny day.
As much as the diversity in colors can be jaw-dropping, what I consider most interesting is the function of the eye and its many secrets.
The eyes have many abilities, and one of those is the ability that the eye has in making tears.
There is so much to know about tears because there are different kinds.
Different types of tears not only serve different purposes, but they’re made up of different substances. Basal tears are constantly keeping our eyes wet and protected, while emotional tears contain high levels of stress hormones that have been found to provide physical relief from pain as well as a decrease in testosterone in men. And reflex tears, which happen in response to some outside irritant, contain antibodies to help keep our delicate eyes healthy.
Tears also clean, lubricate, and moisten the part of the eye that is exposed to air so that it does not dry. It’s probably why some people blink and then their eyes sting. It’s because they went so much time without blinking and they started to dry. Only humans express emotions, both happiness, and sadness, by crying.
Have you ever asked yourself why your head hurts after you are done crying?
When you have a really intense cry, you might feel really awful when you’re done. Your throat gets dry and your head is pounding. Here’s why.
When you start sobbing, stress hormones are released. These hormones naturally cause changes in your body, including headaches among other things. For some people, the headache can be light and for others, well let’s just say it feels like you banged your head against a pole by accident.
Tears are also flowing down your cheeks that are filled with water, so you are losing a little bit of hydration with each one. The problem starts when you have a long cry. That’s when dehydration might set in, no matter how slight, and give you a headache. It happens.
Then there are the tears that wind up going into the nasal cavity, which is why you feel that stinging and burning that often comes with crying. They can also lead to a runny nose. Some people are very sensitive to things like this, and the result is a headache. Ick!
A headache can also result over what exactly caused you to cry, so basically immense amounts of stress.
Well, it gets even better.
In some ways the eye is like a camera: Its optical elements focus on an image of some object on a light-sensitive “film”- the retina-while ensuring the amount of light makes the proper exposure.
Images focused on the retina are inverted (upside down). They also undergo right-to-left reversal that is, light from the right side of an object strikes the left side of the retina and vice versa.
The reason the world does not look reversed is that the brain “learns” early in life to coordinate visual images with the orientation of the objects. The brain stores the inverted and reversed images we acquire when we first for and touch objects and interprets those visual images as being correctly oriented in space.
Light rays from objects closer than 6 meters (20 ft) are divergent rather than parallel instead of those images that are more than 6 meters away. The rays must be refracted more if they are focused on the retina. This additional refraction is accomplished by changes in the shape of the lens.
A normal adult eye is also divided into three layers which are the: Fibrous tunic, Vascular tunic, and the Retina.
But then these layers also have their own separate layers. This makes it all the more confusing and interesting.