31 results about "Spherical equivalent" patented technology

The invention discloses a subjective optometry instrument which comprises an imaging lens and a marker, wherein the front surface of the cornea of a testee is located at a focal point of the imaging lens, the marker and the eye of the testee are respectively located on the two sides of the imaging lens along the optical axis of the imaging lens, the marker can move forward and backward along the optical axis of the imaging lens after being set, the subjective optometry instrument marks a value D1 used for distinguishing the spherical equivalent along the moving path of the marker, a moving position x is obtained by subtracting the focal distance f0 from the object distance of the marker, and when the eye of the testee sees clearly the marker, the spherical equivalent of glasses to be worn on the eyes of the testee is the corresponding spherical equivalent D1 at the moving position x of the marker. The invention further discloses a subjective optometry method. Different from the traditional scheme, the positions of an eye lens and the human eye are needed to be moved to implement refraction compensation in the traditional scheme, the optometry method and the optometry instrument are not required to move the human eye and the lens, but only the marker is moved. When the optometry instrument and the optometry method are adopted in optometry, simplicity and convenience can be achieved, and the cost is low.

A method for estimating and tracking refractive error progression of an individual includes estimating a percentile of Spherical Equivalent Refraction (SPHEQ) as a function of at least the individual's age by comparison to a reference population; estimating an expected SPHEQ trajectory over a future predetermined period of time; comparing the expected SPHEQ trajectory with the reference population; and comparing the expected SPHEQ trajectory with an expected SPHEQ trajectory using an ametropia control treatment, thereby showing a possible treatment benefit over the predetermined period of time.

The invention discloses a method for measuring bubbles in a water body. The method comprises a bubble image identification process, a non-spherical bubble equivalent particle size conversion process and a bubble particle size inversion calculation process. By use of the bubble image identification process, bubble images and suspension images in the water body can be accurately distinguished from each other, and accurate bubble contours are obtained. By use of the non-spherical bubble equivalent particle size conversion process, errors in an equivalent conversion process can be reduced, and the calculation precision of equivalent spherical bubble particle sizes is improved. By use of the bubble particle size inversion calculation process, physical dimensions of bubble particle sizes are generated through combination of image calibration and inversion calculation. The precision is high, the real-time performance is good, original-position real-time measurement of physical parameters of the bubbles can be realized, and the method is suitable for wide application in such fields as scientific research, teaching, seawater monitoring and the like.