JPS5947286B2 - Slide rule for preparing oblique glasses - Google Patents

Description

[Detailed description of the invention] The present invention relates to a slide rule for preparing oblique eyeglasses.

When there is an imbalance between the 6 types of eye movements (front, upper, lower, inner, and outer) and the two upper and lower oblique muscles, parallel vision with both eyes becomes impossible in the so-called resting position of the eye muscles. Not done. This condition is called plagioplasty. Strabismus occurs when this imbalance becomes even worse and parallel vision cannot be achieved even with the use of the eye muscles. Strabismus is not noticeable to others, but some of the eye muscles are used specifically to maintain parallel vision, which causes fatigue, so it becomes necessary to correct it with prism lenses to alleviate this. . To correct phoria, it is necessary to prepare a prism lens with an appropriate phoria direction and power.

The skew power is 1 prism diopter (expressed as P1△), which is the power to shift the line of sight by 1 cm in lm ahead.
is used. On the other hand, the tropism of the eyeball is measured using a Maddox rod, etc., which is a prism with a fixed apex angle and a base in one of four orthogonal directions: upward, downward, internal, and external. In some cases, it is represented by two prisms having bases in any two of the four directions.

In order to correct strabismus, a prism/lens for correcting strabismus is usually prepared by treating both eyes as one unit, making the direction the same for both eyes, and distributing the power equally to both eyes. This corrective prism lens naturally has a fixed power in a certain direction, so if the J measurement result shows 2 base directions and 2 powers, calculate 1 direction and 1 power by combining these. The need arises. The calculation in this direction is the calculation of tan-1y/x, and the calculation of the power is the calculation of ~'[inversion i-.

These calculations are not something that anyone can do easily, so it would be convenient if the combined direction and power could be found instantly analogously without calculations. Therefore, an object of the present invention is to provide an easy-to-use slide rule for preparing oblique eyeglasses that does not require these calculations.
The slide rule of the present invention which achieves this objective consists of a fixed rectangular rule and a rotating fan-shaped rule, the fixed rectangular rule representing a prismatic diopter.

The vertical axis consists of equally spaced scales from to 5 and 5←o→5←o
→ A combination of rectangular coordinates I, ■゜, ■, ■ consisting of the horizontal axis that repeats the symmetrical value of 5 twice, and the point 5 in I from the right
, On the straight line or circular arc connecting 0 and points 0, 5, the angle scale is 0 → 90° with the point 0, 0 as the center, and on the straight line or circular arc connecting the points 0,5 and 5,0 in ■ 90° → 180°,
The angle scale centered on point 0,0 in ■ is point 5,0 and point 0.
, 5 on the straight line or arc connecting 180° → 270°, ■
Point inside. 27 on the straight line or arc connecting 0,5 and point 5,0
The scale is 0° → 360°, 1. ■ upward, ■. ■Downward, 1. ■． ■． ■ is added with the symbol for right eye: medial, lateral, lateral, medial, left eye: lateral, medial, medial, lateral, and the fan rotation scale is the upper point 0 , a fan-shaped transparent body that rotates around 0, and a prism with the point 0, 0 as the center.
Diopt. Represents Thor. It is characterized by having equally spaced circular arc scales from 6 to 6. EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be specifically described with reference to embodiments of the drawings.

In order to facilitate understanding of the function of the slide rule of the present invention, a method of displaying binocular tropia will be explained with reference to FIG.

Both eyes are represented by two circles arranged horizontally. Standing in the patient's position, the right circle in the figure represents the left eye, and the left circle represents the right eye. from 360
It is expressed by marking the angle scale at (=0). Then, the 1, ■ quadrant above the horizontal line is upward (Up), the lower ■, ■ quadrant is downward (DOwn), the left side of the right eye (diagram) is outward (0ut),
The left side (figure) is expressed as inner and outer (In), the left side (figure) of the left eye is expressed as inner (In), and the right side (figure) is expressed as outer (0ut).
Such notation conventions are also carried over to the slide rule of the present invention. FIG. 2 shows an example of the fixed rule of the slide rule of the present invention, and 1, ■, ■, ■ correspond to those in FIG. 1 and represent quadrants. There is no need to write these I, ■, ■, ■ on the slide rule. Looking at the frequency scale of the horizontal and vertical axes, 1 and ■ are objects, ■ and ■ are also objects, and (I, ■) and (■, ■) are the same. Both the horizontal and vertical axes are graduated in prism diopters from o to 5. It is convenient to have a grid-like scale in each quadrant. Then, centering on the two points 0,0,
The angle is I quadrant o → 90°, ■ quadrant 90° → 180°,
It is graduated as follows: ■ Quadrant 180° → 270°, ■ Quadrant 270° → 360°. Furthermore, I, ■ are on the top, ■, ■ are on the bottom, and then I, ■, ■, ■ are in the order of right eye: inward, outward, outward, inward, left eye: outward, inward, It is labeled inward and outward.
FIG. 3 shows an example of a fan-shaped rotating slide rule of the present invention.

This is pivoted so as to rotate around the point 0,0 of the right eye in FIG. The prism diopter scale is graduated from 0 to 6Δ with the point 0,0 as the center. It is convenient to provide straight lines Cl, C2, and C3 at the center and both sides of the sector. Next, how to use the slide rule of the present invention will be described. Example 1 When the results of the tropia measurement are distributed as P2A base medial, P1'' base superior for the right eye, P26 base medial for the left eye, and PIA base inferior for the left eye, points 2 and 1 are located within the I quadrant of the fixed slide rule. be synthesized.

This direction is 26.5 degrees, and the size is the length of the straight line connecting points 0, 0 and 2, 1, which is 2.2 on the arc scale of the fan-shaped rotation scale.
It is read as At this time, it is best to align the straight line that is easier to use among Cl, C2, and C3 so as to pass through points 2 and 1. Furthermore, a straight line connecting points 0, 0 and 2, 1 is drawn in quadrant 2, and 206.5° and 2.2 are read in the same way. That is, the composite value is a right eye P2.2A base of 26.5° and a left eye P2.2A base of 20°.
It becomes 6.5°. In the end, it is sufficient to prepare such a prism lens. Example 2 If the binocular distribution of the measurement results is right eye Pl6 base lateral, P3△bouki lower, left eye P1△kisho sogao, P3△base upper, then ■ Inlay points 0, 0 and A straight line connects points 1 and 3, and a straight line connects points 0 and 0 and points 1 and 3 in the I quadrant.

Find the direction and length in the same way as Example 1, and find 251.5°, 3
．． 2, and 71.5°, 3.2 are found. That is, the composite value is a right eye P3.2A base of 251.5° and a left eye P3.2Δ base of 71.5°.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional method of displaying the results of measuring right and left eyes.

Claims (1)

[Claims] 1. Consists of a rectangular fixed scale and a fan-shaped rotating scale, and the rectangular fixed scale is symmetrical with the vertical axis consisting of equally spaced scales from 0 to 5 representing prism diopters at 5←0→5←0→5. Cartesian coordinates consisting of two repeating horizontal axes I, II, II
A combination of I and IV, and points 5, 0 and 0 within I from the right
, on the straight line or arc connecting points 0, 5, angle scale 0 → 90° with point 0, 0 as the center, 90° → 180° on the straight line or arc connecting points 0, 5 and points 5, 0 in II , set the angle scale from 180° to 270° on the straight line or arc connecting points 0 and 5, and point 0 in IV.
, 270° → 36 on the straight line or arc connecting 5 and points 5 and 0
0° is the scale, I and II are upwards, III and IV are downwards, I,
II, III, IV right eye: medial, lateral, lateral, medial, left eye:
The symbols for outer, inner, inner, and outer are added,
A fan-shaped rotation scale is a fan-shaped transparent body that rotates around the upper point 0, 0, and is graduated with equally spaced circular arc scales from 0 to 6 representing prism diopters around the point 0, 0. A slide rule for preparing oblique glasses.