opacity of refractive medium
Introduction
Introduction When the refractive medium of the eye (such as the cornea, crystal, vitreous, etc.) becomes turbid or there is ametropia (including myopia, hyperopia, astigmatism, etc.), even the eyesight of the retina functioning well will decrease. The refractive medium of the eye is turbid and can be treated with surgery, while ametropia requires lens correction.
Cause
Cause
Eye refractive energy is opaque due to ocular trauma or other eye diseases such as vitreous hemorrhage, resulting in decreased vision.
Examine
an examination
Related inspection
Eye and sacral area CT examination
Refraction is a method of diagnosing vision problems. The optometrist will determine the refractive status of the guest according to some procedures and with the help of the instrument to determine whether there is ametropia, such as myopia, astigmatism, hyperopia or presbyopia. Under normal circumstances, we will conduct objective and subjective refractive examinations for each case in order to achieve reliable diopter.
Objective Refraction
The optometrist will use a special instrument, the Retinoscope, with Retinoscopy to illuminate the pupils of the guest, and then determine the diopter according to the direction in which the reflected light travels. This method is highly reliable and suitable for people who are not easy to express themselves, such as children, deaf and mentally handicapped people. The use of reconnaissance requires long-term and rigorous professional training to master, but the general practice of optometrists Happy to use.
Computer Eye Tester (Auto Refractor)
Auto Refractor is another common method of objective refractive examination, but it can't be used as a refractive prescription or visual care if it is based on computer vision alone.
Diagnosis
Differential diagnosis
The turbidity of the refractive medium requires a differential diagnosis from the following symptoms:
First, myopia
Seeing the near object is clear, looking far away, the professional definition is "a distant object is focused on the front of the retina after being refraction of the eyeball, rather than forming a clear object image on the retina." Myopia is the most common eye disease in Chinese children, and the ratio of high myopia in the mainland is much higher than that in other countries and regions. Many eye diseases caused by high myopia are threatening the vision and eye health of many children.
Second, hyperopia
A distant object is focused on the retina after being refraction through the eyeball, and a blurred virtual image is formed on the retina. Therefore, it is unclear for patients with hyperopia to look far and near. Infants and young children have few myopias, and more than 90% of preschool children are hyperopia, most of which are physiological and are the normal development of the eye. 20%-25% of hyperopia is pathological, which is the main cause of low vision and ocular dysplasia in children.
Third, amblyopia
Amblyopia is a disease that seriously affects visual function. It refers to those patients whose eyeballs have no obvious organic lesions and whose near and far vision are below 0.8, and they cannot be positive. According to statistics, the number of patients with amblyopia has exceeded 15 million, which has become a social issue that everyone needs urgent attention. Refraction is a method of diagnosing vision problems. The optometrist will determine the refractive status of the guest according to some procedures and with the help of the instrument to determine whether there is ametropia, such as myopia, astigmatism, hyperopia or presbyopia.
