Table 1

Non-cycloplegic subjective refractions (SR) were independently measured for each eye by 50 experienced optometrists (>5 years)

Right eyeLeft eye
Means: F (D or m-1) Embedded Image Embedded Image
Means: f (D or m-1 ) Embedded Image Embedded Image
Means (Embedded Image ): Embedded Image Embedded Image
Clinical notation (D, D, °)
Variance–covariance matrices (D2) Embedded Image Embedded Image
Volumes (D 3 )
95% distribution ellipsoids18.9521.976
95% confidence ellipsoids0.0640.007
Mean excesses
Scientific notation (D)–0.0000I+0.0000J – 0.0000K 0.0000I – 0.0000J – 0.0004K
Clinical notation (D, D, °)–0.00–0.00×1450.00–0.00×129
Norms or magnitudes of mean excesses (D)0.0000.000
  • The sample means are given using three methods, namely, using dioptric power matrices (F)—see Equation 1 above, transposed coordinate vectors (f)—see Equation 5 for the same but as column rather than row vectors, and standard or clinical notation (F s F c A). Variance-covariance matrices and the volumes for 95% surfaces of constant probability density (SCPD), that is, 95% distribution and confidence ellipsoids on means (CEM) are also included. Excesses (see later) of SR and the criterion-standard, either Embedded Image OD or Embedded Image OS as applicable, are also included.