In night blindness, medically called hemeralopia, vision at dusk is impaired. Responsible for this is a functional weakness of the rods. These are the sensory cells of the retina that enable vision in low light conditions. What is night blindness? Night blindness can be congenital, but it can also be caused by a condition such … Night Blindness: Causes, Symptoms & Treatment
Synonyms (Opticus = optic nerve; atrophy = decrease in cell size, decrease in cell count) Death of the optic nerve, optic nerve atrophy Definition Optic atrophy Optic atrophy is the loss of nerve cells in the optic nerve. The nerve cells either decrease in size or in number. Both are possible. Atrophy can have various … Optic atrophy
The retina is located on the back of the inner wall of the eye and is instrumental in creating image information for the brain. Age, disease, and congenital disorders can impede the function of the retina, which has a complex structure, in many ways. A large number of successful therapeutic procedures exist. What is the … Retina: Structure, Function & Diseases
Usher syndrome is a gene mutation of various chromosomes that causes hearing-vision impairment of various degrees of severity. The most severe form, with congenital deafness and visual field loss, presents at age ten. While the partially progressive hearing impairment is treated with a hearing aid and later a chochlear implant, no therapeutic methods are yet … Usher Syndrome: Causes, Symptoms & Treatment
Diabetic retinopathy is a change in the retina that occurs over the years in diabetics. The vessels of the retina calcify, new vessels can form, which grow into structures of the eye and thus severely endanger vision. Bleeding also occurs in diabetic retinopathy. Depending on the stage of the disease, deposits, new vessels or even … Diabetic Retinopathy
What are typical risk factors? Typical risk factors for diabetic retinopathy are, as the name suggests, factors that are particularly prevalent in diabetics. This includes in particular a badly adjusted and over a long period of time increased blood sugar. The sugar is deposited as large molecules in the walls of the blood vessels. This … What are typical risk factors? | Diabetic Retinopathy
Photoreceptors are light-specialized sensory cells on the human retina. They absorb various electromagnetic light waves and convert these stimuli into bioelectrical excitation. In hereditary diseases such as retinitis pigmentosa or cone-rod dystrophy, the photoreceptors perish bit by bit until blindness occurs. What are photoreceptors? Photoreceptors are light-sensitive sensory cells that are specialized for the visual … Photoreceptors: Structure, Function & Diseases
Synonyms in a broader sense Medical: Hemeralopia Definition Night blindness is a disturbed adaptability of the eyes to darkness. For those affected, only outlines can be seen. The adaptation of the eyes to light is very fast, while adaptation to darkness takes a very long time, 30 to 50 minutes. Summary Night-blind are people whose … Night blindness
Diagnosis Night blindness is detected by the ophthalmologist (specialist in ophthalmology) using tests. First and foremost, however, discussions between doctor and patient are informative. Devices like the nyctometer or mesoptometer are used. These measure the twilight visual acuity. They test the performance of the visual organ between daytime vision and complete adaptation to darkness. Patients … Diagnosis | Night blindness
Vitamins are substances that are used in small quantities for metabolic control and that are not formed in the human organism. Therefore, they must be supplied with food. Importance of vitamins Vitamins are substances that are needed in small quantities for metabolic control and that are not formed in the human organism. Vitamins are especially … Vitamins: Function & Diseases
In a study from 2006 to 2007, it was found that MRI can be used to measure the thickness of the optic nerve. If there is a loss of nerve fiber (optic atrophy), this becomes visible on MRI examination as a decrease in the diameter of the optic nerve thickness. This method using the 3T … MRI for optic atrophy
What is the MRI procedure for optic atrophy? The patient is pushed into the MRI machine lying on an examination table. The area of the body to be examined, in this case the head for ophthalmology, is brought into position so that it is level with the device. Then the sectional images of several layers … What is the MRI procedure for optic atrophy? | MRI for optic atrophy
