Skiascopic Ruler

Skiascopic rulers are special devices that are used to determine the refraction of the eyes. They are a frame with sets of lenses that can be changed as needed. In the process of measuring refraction, the doctor first determines the distance between the eye and the lens, and then changes lenses in the frame and continues the measurement until the optimal lens is found that allows the eye to see as clearly as possible.

Skiascopic lenses can be either collecting or diverging, depending on what refraction needs to be determined. Converging lenses help increase the power of vision, while diverging lenses help reduce it.

To measure refraction using a skiascopic ruler, the doctor first determines the distance from the eye to the lens and records it on the scale. He then changes lenses in the ruler and continues measuring until he finds the optimal lens that allows the eye to see most clearly.

Introduction

A skiascopic lens is an optical device that is used to determine the refraction of the eye and its accurate diagnosis in various eye diseases. It is often used by optometrists and ophthalmologists to diagnose vision problems. Today we will look at how the skiascopic device works and how it helps in determining the correct diagnosis and treatment.

Basic principles of operation of a skiascopic lens

1. The principle of the device. The lens is attached to a plate with parallel guides. Differently armed magnifying glasses are loosely installed on the guide. When turned over in the head of the setting button (eyepiece), a beam of light is turned on, acting on the tip of the lens. The beam lens is then rotated to any of the positions. When the glass becomes vertical, an image of a slit beam will appear on the screen if there are no obstacles. Sometimes the image appears with a different eyepiece position. It can only be reflected correctly at the top point of the screen. In this position, the image of the beam is called relief. If the rays pass normally through the cornea and the fundus of the eye, then at the convex point a deep shadow will appear, reminiscent of a concave reflection. This method of observation was considered for all types of ametropia and astigmatism. Now let's consider a more common case - the absence of ametropia, or the norm. Then, for any position of the lens, a clear image of the beam is observed. If it is directed at the convex surface of the plane script, then after the refractive coating a deep carving will appear on it. The direction of the beam here marks the boundary of normal vision. ⠀ If there are more vision deficiencies in the future (for example, -0.5 diopters), or if this is not yet clear with astigmatism of the eye glasses, then an imprint of the cornea is made through the tube. The position of the light rays is checked and the lenses are moved to obtain a print. The measurement of such a ruler is carried out using an instrumental beam of light. A relief check of the cornea is carried out in 4 places. In the future, well-aligned eye geometry is recommended only once. To correctly apply retinotropy, special devices are used: retinoprobes, retinoplegs. The diagnosis is carried out by two ophthalmologists: one doctor is responsible for the visual test, the second checks the position of the lens head and records the final results. After measuring the refractive power, protection from foreign objects and muscles is put on the eye - orthokeratology lenses. They help close your eyelids tightly. This is necessary to check your refraction. During replacement, standard farsightedness tests are performed if the patient has a defect in glasses or anti-burn plastic lenses. Dosage for treatment is carried out only for further hypermetropia. Visual impairment is corrected in children and adults with orthoplegic glasses. Taking additional exams on your own leads to strong reactions, such as insomnia or fear. Therefore, it is better to entrust the diagnosis to qualified specialists; they will carry out all the necessary treatment painlessly and professionally.