Ultraviolet rays are the component of sunlight and is divided into UV-A and UV-B and UV-C radiation. UVA rays tan skin and is due to premature skin aging. UV-B rays cause sunburn and are often associated with skin cancer and eye problems such as cataracts. UV-C rays are most dangerous. There are, fortunately, blocked by ozone layer and do not get to the earth's surface.
Your eyes tell you not only about whether your vision is good or bad but also about your health in general. They can be regarded as windows through which a doctor can assess your general health. Besides the eyes no other organ enables such an easy examination of the state of your veins and arteries. Many metabolic disorders exhibit on blood vessels and therefore the eyes play a crucial role in early diagnosis. Your eyes can exhibit the early symptoms of diseases which can influence your sight. Therefore regular eye examinations are important even though you do not have problems with your sight. Your eyes tell the story about your health and the information can be interpreted only by your ophthalmologist. During eye examination he focuses on these symptoms:
Accommodation of the eye is the ability of the human eye to see sharply all objects which are located at various distances in front of the eye depending on the changes of massiveness of the optical system of the eye. The mechanism of eye accommodation is not the same for all animals. For example fish accommodates through the change of position of the lens, some types of birds accommodate through the increase of curvature of the cornea and protraction of the human eye. As far as humans are concerned accommodation is caused by the increased curvature of anterior area of the eye lens while at the same time its thickness also changes. Accommodation is usually the same on both eyes.
When driving a motor vehicle a driver has to continuously monitor not only what is happening on the road but also the data on the panel board. The tilting of his head (in average around 30 degrees) leads to reduction of the sharpness of the image of events happening on the road which is caused by the movement of the eyes. When looking at the speedometer the movement of the eyes exceeds the target by 5 degrees in average and it is immediately balanced with the subsequent movement of the eyes. The creation of sharp image on the retina leads to its processing and to the realization of what is seen. However, we suppose that the size of the figures, which are being read, has to be at minimum 5 times bigger than the minimal size which enables them to be differentiated. Therefore the look can return to the original position only after the processing and implementation of the information.
The color vision is a very complicated psychophysical process during which human eye distinguishes different colors. From the physical point of view the color does not exist and it is only a visual perception which is conditioned by the wavelength of the light. The certain part of the spectrum reflects from different objects, then it falls on the eye where it causes the irritation of the light sensitive elements which react to colur – the cones. For its realization, it is necessary to have a correct and undisturbed function of the eyesight and the human eye as the receiving organ, the optical path as the transmitting system and the centers of the brain thanks to which we distinguish and thus they are the analyzer of the perception.
Human eyesight is a sense which enables animals to perceive the light, different colors, shapes and it serves to the general perception of the environment. It is oriented mainly towards the perception of contrast and thus even contours and it significantly helps with orientation in space. For a human being the eyesight is the most important sense and that is mainly because almost 80% of information from our surroundings is perceived through it.
Your eyes tell you not only about whether your vision is good or bad but also about your health in general. They can be regarded as windows through which a doctor can assess your general health. Besides the eyes no other organ enables such an easy examination of the state of your veins and arteries. Many metabolic disorders exhibit on blood vessels and therefore the eyes play a crucial role in early diagnosis. Your eyes can exhibit the early symptoms of diseases which can influence your sight. Therefore regular eye examinations are important even though you do not have problems with your sight. Your eyes tell the story about your health and the information can be interpreted only by your ophthalmologist. During eye examination he focuses on these symptoms:
When driving a motor vehicle a driver has to continuously monitor not only what is happening on the road but also the data on the panel board. The tilting of his head (in average around 30 degrees) leads to reduction of the sharpness of the image of events happening on the road which is caused by the movement of the eyes. When looking at the speedometer the movement of the eyes exceeds the target by 5 degrees in average and it is immediately balanced with the subsequent movement of the eyes. The creation of sharp image on the retina leads to its processing and to the realization of what is seen. However, we suppose that the size of the figures, which are being read, has to be at minimum 5 times bigger than the minimal size which enables them to be differentiated. Therefore the look can return to the original position only after the processing and implementation of the information.
The color vision is a very complicated psychophysical process during which human eye distinguishes different colors. From the physical point of view the color does not exist and it is only a visual perception which is conditioned by the wavelength of the light. The certain part of the spectrum reflects from different objects, then it falls on the eye where it causes the irritation of the light sensitive elements which react to colur – the cones. For its realization, it is necessary to have a correct and undisturbed function of the eyesight and the human eye as the receiving organ, the optical path as the transmitting system and the centers of the brain thanks to which we distinguish and thus they are the analyzer of the perception.
Human eyesight is a sense which enables animals to perceive the light, different colors, shapes and it serves to the general perception of the environment. It is oriented mainly towards the perception of contrast and thus even contours and it significantly helps with orientation in space. For a human being the eyesight is the most important sense and that is mainly because almost 80% of information from our surroundings is perceived through it.