DOI QR코드

DOI QR Code

중첩된 시험렌즈의 합성굴절력에 대한 신뢰도 평가

The Evaluation of Reliability for the Combined Refractive Power of Overlapping Trial Lenses

  • 이형균 (서울과학기술대학교 안경광학과) ;
  • 김소라 (서울과학기술대학교 안경광학과) ;
  • 박미정 (서울과학기술대학교 안경광학과)
  • Lee, Hyung Kyun (Dept. of Optometry, Seoul National University of Science & Technology) ;
  • Kim, So Ra (Dept. of Optometry, Seoul National University of Science & Technology) ;
  • Park, Mijung (Dept. of Optometry, Seoul National University of Science & Technology)
  • 투고 : 2015.08.17
  • 심사 : 2015.09.07
  • 발행 : 2015.09.30

초록

목적: 구면렌즈와 원주렌즈를 시험테에 중첩하였을 때 합성굴절력의 신뢰도를 알아보고자 하였다. 방법: 마이너스 구면 시험렌즈와 원주 시험렌즈의 굴절력, 중심두께 및 주변부두께를 측정하였으며 구면 시험렌즈와 원주 시험렌즈를 장입순서를 바꿔가며 시험테에 중첩되었을 때의 굴절력을 자동렌즈미터로 측정하여 합성굴절력 계산값과 비교 평가하였다. 결과: 시험렌즈의 중심부와 주변부의 두께증감이 도수의 증감과 상관성을 보이지 않았으며 79개 시험렌즈 중 3개의 시험렌즈에서 국제기준규격(ISO-9801)에서 벗어난 굴절력이 측정되었다. 정점간거리를 보정하는 굴스트랜드 공식 굴절력값이 얇은 렌즈 공식 굴절력값보다 실측값과의 오차가 적었으나, 여전히 실측값과는 통계적으로 유의한 차이가 있었다. 굴절력의 크기는 원주렌즈와 구면렌즈의 위치와 상관없이 평균적으로 얇은 렌즈 공식 굴절력값 > 실측 굴절력값 > 굴스트랜드 공식 굴절력값 순으로 나타났다. 구면렌즈가 안쪽, 원주렌즈가 바깥쪽에 장입되었을 경우에는 굴스트랜드 공식에 대입하였을 때 원주굴절력만 오차가 발생하지만 원주렌즈가 안쪽, 구면렌즈가 바깥쪽에 장입되었을 때는 구면굴절력과 원주굴절력 모두에서 오차가 나타났다. 실측값의 등가구면굴절력을 비교하였을 때 구면렌즈가 시험테의 안쪽, 원주렌즈가 시험테의 바깥쪽에 장입된 경우가 정확도가 더 높았으며 과교정의 우려가 작았다. 결론: 본 연구 결과 시험렌즈테에 렌즈를 중첩하였을 때의 합성굴절력은 정점간거리 외에도 중첩되는 렌즈의 두께와 광학중심 등의 영향을 받으며 구면렌즈와 원주렌즈의 중첩 순서에 따라 굴절력에 차이가 있으므로 이에 대한 기준의 정립이 필요함을 제안한다.

Purpose: The current study aimed to evaluate the reliability for the combined refractive power when a spherical lens and a cylindrical lens were overlapped in a trial frame. Methods: The refractive powers, central thickness and peripheral thickness of spherical trial lenses and cylindrical lenses with negative power were measured. The combined refractive power of the spherical and cylindrical lenses was measured by auto lens meter. Measurement was repeated by changing the insertion order, and their results were further compared with the calculated combined refractive power. Results: There was no correlation between the variation of central and peripheral thickness in trial lenses and that of the lens power. Among 79 trial lenses, 3 trial lenses wasn't met the international standard. The refractive power calculated by Gullstrand's formula that could compensate vertex distance had smaller difference with the estimated power when compared with that calculated by thin lens formula however, it was significantly different from the estimated power. The refractive powers were generally apparent regardless of the insertion order of a spherical lens and a cylindrical lens: thin lens formula > actual measurements > Gullstrand's formula. The error was only found in cylindrical power calculated by Gullstrand's formula when inserted a spherical lens inside and a cylindrical lens outside however, the error was found in both of cylindrical and spherical powers calculated by Gullstrand's formula when inserted as a opposite order. By comparing actual measurements of equivalent spherical power, the accuracy was higher and the possibility of over-correction was lower when inserted a spherical lens inside and a cylindrical lens outside. Conclusions: From the results, those were revealed that the combined refractive power is influenced by the factors other than the vertex distance and the refractive power varies in accordance with the insertion order of a spherical lens and a cylindrical lens. Thus, it can be suggested that the establishment of standard for these is neccesaty.

키워드

참고문헌

  1. Kang HS. An introduction to visual optics, 2nd Ed. Seoul:Shinkwang, 2004;25-27.
  2. Park SY, Mun BY. Research on the actual state of domestic trial lens. Korean J Vis Sci. 2007;9(4)401-412.
  3. Chun YS, Kim HS, Lee JU, Park SC. Optical design of cemented doublets by using equivalent lens system. Korean J Optics Photonics. 1998;9(5):282-290.
  4. Kim JK, Kang MG. A study of the power of glasses lens and that of trial lens. J Korean Ophthalmic Opt Soc. 1998;3(1):263-267.
  5. Lee JU, Kim KS. Generalization of equivalent lens conversion and third order aberration formulae of the generalized equivalent lens system. Korean J Optics Photonics. 1996;7(4):305-313.
  6. Lee JU, Park SC. Generalized lens group conversion to their equivalent lenses. Korean J Optics Photonics. 1998; 9(4):251-257.
  7. Moon BY. Comparative analysis of refractive power on trial case Lenses. J Korean Ophthalmic Opt Soc. 2012;1 7(4):321-334.
  8. Seo JK, Jo YN, Sim HS, Kim SH. A study on the spherical aberration and astigmatism of sports sunglass. Korean J Vis Sci. 2013;15(2):101-111.
  9. Kim SK, Sung AY. The clinical study on spectacle wearers of high school students. J Korean Ophthalmic Opt Soc. 2004;9(1):19-27.

피인용 문헌

  1. Evaluation of Reliability for Combined Refractive Power of Lenses in an Automatic Phoropter vol.20, pp.4, 2015, https://doi.org/10.14479/jkoos.2015.20.4.501
  2. Evaluation of Reliability for Spectacles Prescription Using Auto Phoropter and Trial Lens vol.24, pp.1, 2015, https://doi.org/10.14479/jkoos.2019.24.1.61