The Eye by
The human eye has been the subject of endless fascination. Indeed, the very nature of sensory perception is shaped by the visual cues the brain receives, thus rendering the eye one of the most crucial elements in our comprehension of the world. The structures and functions of the eye are examined in this exhaustive volume that describes how we are able to process what we observe and react accordingly. Detailed diagrams accompany the text and encourage the reader to consider all aspects of this beautiful and complex area of human anatomy.
Help for Auditory and Visual Processing Disorders Strategies for parents and teachers by
"The strategies address the challenges of parents, tutors and teachers on teaching individuals with Learning Disabilities so as to give the child a far better chance at being happy and successful in their schooling, career, social life's and later heading into adulthood."
Blindness & Vision Disorders
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Cataracts: imperfections in the clarity of the eye lens that reduce its ability to transmit light. Symptoms: Loss of clear vision, typically one eye at a time Cause: Aging, diabetes, injury, exposure to x-rays or nuclear radiation, congenital defect Treatment: Surgery Diabetes Mellitus: An endocrine disorder characterized by hyperglycemia due to autoimmune destruction of insulin-secreting pancreatic beta cells or from variable degrees of insulin resistance and deficiency. Symptoms: Large urine output, excessive thirst, dehydration, low blood pressure, weight loss despite increased appetite, fatigue, nausea, vomiting, blurred vision Cause: Genetic and environmental factors Treatment: Insulin or oral hypoglycemic drugs, lifestyle changes (diet modification and exercise) Glaucoma: Glaucoma is a group of eye diseases characterized by damage to the optic nerve Symptoms: Often asymptomatic; eye pressure; slow progression toward blindness; at times, pain, nausea, vomiting, severe headaches. Cause: Congenital or hereditary factors; anatomic factors (smaller eye length, shallower anterior chambers); drugs; tumor; trauma; inflammation Treatment: eye drops, ointments, pills, and surgery using both incisions and lasers Macular degeneration: A degenerative disease of the central portion of the retina that results primarily in loss of central vision Symptoms: Dependent on form; can include blurred or distorted central vision, bleeding within and beneath retina, development of scar tissue, eventual blindness Cause: Unclear; possibly aging, genetic factors, nutrition, smoking, sunlight exposure Treatment: Vision aids (e.g., magnifying glasses, special lenses, electronic systems); laser photocoagulation; surgery; low-level radiation; injection of photosensitive chemicals into bloodstream Nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. Cause: The cornea-lens focusing system of the eye bends light rays either too much or too little resulting in a blurred image. Treatment: eyeglasses or contact lenses. Trachoma: Contagious infection of the eyelid similar to conjunctivitis (commonly known as pinkeye). Symptoms: Red, painful, and sticky eyes; irritation to underside of eyelid; turning in of eyelid and eyelashes with corneal damage; eventual blindness untreated, it causes scarring of the cornea and eventual blindness. Cause: Chlamydia trachomatia bacteria, It is carried primarily by children throughout the developing world, where water is scarce and washing is difficult. Treatment: Tetracycline eye ointment, face cleansing, surgery if prolonged |
This video explores the causes of vision impairment, including: uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%).[5] Refractive errors include near-sightedness, far-sightedness, presbyopia, and astigmatism.[5] Cataracts are the most common cause of blindness.[5] Other disorders that may cause visual problems include age-related macular degeneration, diabetic retinopathy, corneal clouding, childhood blindness, and a number of infections.
Vision is More Than 20/20 is a podcast aimed at talking about vision, your eyes and how they play a role in overall visual and systemic function.
