The human eyes work by allowing light to enter and project onto a light sensitive panel of cells known as the retina at the rear of the eyes, where the light is detected and converted into electrical signals. These are then transmitted to the brain via the optic nerve.
Total blindness is the complete lack of form and light perception and is clinically recorded as "NLP," an abbreviation for no light perception.
Legal blindness. In North America and most of Europe, legal blindness is defined as visual acuity (vision) of 20/200 (6/60) or less in the better eye with best correction possible.
There are many diseases, disorders, and age-related changes that may affect the eyes.
This series of articles provides some useful information on the human eyes, vision and products including screenreaders for the sight impaired and/or blind.
What Is Glaucoma? Glaucoma is a family of diseases that can damage the eye's optic nerve and result in vision loss and in most extreme cases, blindness. Nutrients Provide Relief for Chronic Dry Eye Sufferers Dry eye is one of the most common, although not serious, eye conditions of middle aged people. It greatly interferes with the quality of life for approximately 14 percent of people over the of age 40. About 21 million people in the United States, it is realistically estimated that figure is probably more like 60 million, reported experiencing chronic dry eye symptoms. Beating the Odds of Developing Glaucoma Glaucoma is a potentially, and very serious, threatening eye disease that can rob you of your ability to see. It is often called the 'sneak thief' of vision for a valid reason. For many people, years often pass with no noticeable affects of having glaucoma before a vision loss is finally noticed. Kajal the Blind Girl from Calcutta The tiny, 5-year-old girl from Calcutta is called Kajal. She is blind because an angry stepmother poured acid in her eyes in a now distant spat in her homeland. How to Put in and Care for Contact Lenses Like most, I've wondered how to put in contact lens easily and quickly. Spending more time than you thought it would, dropping the lenses, your eyes start getting sore, you are getting frustrated ... sound familiar? Computer Vision Syndrome The average American child spends almost one to three hours a day sitting in front of the computer. They have homework to do, friends to chat with, and video games to beat. All of this while sounding fun, can be quite a strain on their eyes. How to Clean Sunglasses By using these basic procedures you can ensure that your sun glasses will last many years and give you unsurpassed performance in providing excellent eye care and unmatched vision enhancement. Vitreous Eye Floaters A 50 year old woman calls our office complaining about little spots and fly like things floating in her vision and occasional flashing lights. We tell her to come in as soon as possible and we do a complete eye and retinal exam. She suffers from Vitreous Floaters, a normal condition. When are you Legally Blind Approximately ten percent of those deemed legally blind, by any measure, have no vision. The rest have some vision, from light perception alone to relatively good acuity. Low vision is sometimes used to describe visual acuities from 20/70 to 20/200. Basic Structure of the Human Eye There are two regions in the iris that contain pigment, or melanin: one is in the IPE, which I have already eluded to, and the other is in the iris stroma. For the most part, the amount and distribution of melanin in the IPE is similar in irides of different colors. Therefore, it is unlikely that the IPE itself is a major determinant of iris color. Printable Snellen Eye Chart Printable Snellen eye chart for home use to determine your visual acuity ie. 20/20 vision. If a person cannot achieve a visual acuity of 20/200 (6/60) or above in the better eye, even with the best possible glasses, then that person is considered legally blind in the United States. A person with a visual field narrower than 20 degrees also meets the definition of legally blind. Ways to Deflate Puffy Eyes When you look yourself up at the mirror and find that your eyes look like they are carrying the weight of the world under them, your whole day will just not feel right anymore. Having puffy eyes is just not something that you are willing to wear to the office or school unless you are born with it. What is 20/20 Vision? 20/20 vision is customary visual acuity. Visual acuity is the ability to see cipher and stuff obviously from a vastness. How to Treat Dark Circles Under Eyes Dark circles under the eyes are caused by a very specific physiological mechanism. There are many contributing factors to the development of these dark circles and even more things that can make them worse. Reduce and Prevent Eye Strain The summer season is already nearing its end, but with such dry weather, your eyes can still be put under a lot of strain. Fortunately, there are a few things you can do to help relieve and even prevent eye strain so you'll be able to keep using those babies for a long time. Guide Dog Facts This article is designed to give an insight to how guides dogs work and what we should be aware of when meeting one in its working environment. What is Macular Degeneration? Macular Degeneration is a condition that affects millions of people worldwide, and has a significant impact on the quality of life enjoyed by its sufferers, however when most people are diagnosed with the disease, they know very little about what is macular degeneration, and what causes it. Herbal and Ayurvedic Home Remedies for Eye Care The importance of the eyes to the human beings need not be emphasized. Eyes provide us sight, without which life would lose most of its meaning. But at the same time, eyes are constantly exposed to the external environment. Bifocal and Toric Contact Lenses Two of the most common contact lens prescriptions prescribed for people today are for the eye conditions of presbyopia and astigmatism. Modern technology has made bifocal and toric contact lens designs available in both the rigid gas permeable (RGP) lenses and the soft lenses, offering more options and wear schedules then ever before. Cataract Symptoms - Surgery and Treatment When protein molecules in the eye's crystalline lens clump together and begin to block light entering our eyes, this is known as cataracts. What is Photodermatitis? Photodermatitis and its Symptoms Photodermatitis is a condition which occurs when the skin has an abnormal reaction to the suns ultraviolet light. There are two types of the condition, either acute Photodermatitis, or Chronic Photodermatitis. Is LASIK Right for Me? The subject of LASIK is a very interesting one. There is a lot to investigate and understand about the process of getting your vision corrected through laser surgery. Ways to Beat Computer Eyestrain If you work in an office, do your eyes hurt by the end of the working day? You aren't alone: about 88% of all people who work with computers experience a type of eyestrain known as Computer Vision Syndrome (CVS). When You Meet a Blind Person Visually impaired people, whether they are totally blind or have some degree of useful vision may, at times, require the assistance of a sighted guide. Protecting your Eyes from the Sun UV radiation can play a contributory role in the development of various ocular disorder, including age-related cataract, pterygium, cancer of skin around eyelids and photokeratitis. Natural Vision Improvement The eyes are very big oxygen consumers in the human body You need to breath a lot of fresh air in every single day. The lack of oxygen leads to poor eyesight, while enough oxygen leads to better eyesight. Lesson to All Drivers I saw a lady with a guide dog pass my window. Before she had managed to disappear from view she stopped.
This article is general information ONLY and is NOT a substitute for medical advice or treatment
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