Modern cataract surgery has significantly improved as a complete surgical procedure, and patient awareness of cataract surgery has been changed beyond the expectations of ophthalmologists. However, some patients are still dissatisfied with their postoperative visual performance, even when the visual acuity is 20/20 or better. Since cataract surgery is increasingly viewed as refractive surgery, it is important to reduce postoperative refractive errors and to improve the predictability of outcomes as much as possible.

The Japanese Society of Cataract and Refractive Surgery Clinical Survey in 2020 showed that the SRK/T formula is still most preferred in Japan. However, this formula can be influenced by axial length and corneal refractive power. To overcome these disadvantages, new generation formulas, such as the Barrett Universal II formula, the Hill RBF method, and the Kane formula, have been proposed, and we are facing a new age of intraocular lens power calculation. A nationwide multicenter study suggests that it is critical to optimize accumulation of biometric data from all institutions.

Purpose: This study aimed to evaluate the correlation between ocular refraction and total, corneal, and internal higher-order aberrations in myopic with-the-rule astigmatism.

Methods: A total of 77 healthy young adults (mean age ± standard deviation, 21.0 ± 0.8) were participated in this study. The objective ocular refraction, coma, trefoil, and spherical aberrations in the right eye were performed three times each using the wavefront aberrometer. The correlation between objective ocular refraction and total, corneal, and internal higher-order aberrations was examined.

Results: Astigmatism was significantly correlated with internal coma and corneal spherical aberrations (internal coma: P = 0.025, corneal spherical: P = 0.010). Spherical power was not significantly correlated with the higher-order aberrations.

Conclusion: These findings suggested that with-the-rule astigmatism was correlated with internal coma and corneal spherical aberrations in healthy young adults with myopia.

We investigated whether the haze, which is the degree of translucent opacity, affects the dynamic range of lightness perception (DRL).

The subjects were 12 eyes (mean age 34.4 ± 9.7 years) without vision problems. We used a visual dynamic range test under the three different background luminance with six different amounts of haze filters. The DRL was defined as the ratio (R) of minimum and maximum perceptible luminance by the test and expressed in dB (10 x log₁₀(R)).

The results showed that the DRL had decreased as the haze increased (F = 8.12, p < 0.01) or as the background luminance increased (F = 31.1, p < 0.01). Both the haze and the background luminance had main effect on DRL (F = 0.618). The amount of shift of the center of the perceptible luminance with changing background (iCS1) was not affected by haze (F = 2.02). The difference of DRL between light and dark background (iCS2) was affected to increase by haze (F = 4.20, p < 0.01). These results showed that the larger haze amount is, the smaller DRL is and the larger iCS2 is. This dynamic range test is a simple and useful method to quantify the visual difficulties other than visual acuity.

Purpose: To investigate the effect of yellow tinted lenses with different spectral transmittance on contrast sensitivity (CS) under glare.

Methods: The subjects were 27 eyes of 27 patients with no eye disease other than refractive error. The CS under glare was measured using the Contrast Glare tester CGT-2000, under photopic, mesopic and scotopic on the visual angle 6.3, 4.0, 2.5, 1.6, 1.0, and 0.64 degrees. The yellow tinted lenses were used 4 types of G1, G2, G3 and G4. Measurements were performed five times in total in each background condition, one with no lens wearing (N) and four with lenses wearing (one for each lens). We investigated the effects of the CS between N and G1, G2, G3, G4.

Results: There was no significant difference under photopic vision, mesopic vision and photopic vision of the CS (p > 0.05).

Conclusion: The results suggested that wearing yellow tinted lenses has no effects on the CS under glare in healthy young people.

So far, we have reported on the ease of viewing when adjusting the distance when wearing an ES lens designed to extend the depth of field (manufactured by Itoh Optical Industrial Co., Ltd.). This time, in order to evaluate the dynamic accommodation function when wearing an ES lens, the equivalent spherical power of the dominant eye was measured using a binocular wavefront sensor, and the accommodation function was evaluated. Although it was a statistical result that there was no difference in equivalent spherical power, it was suggested that by wearing an ES lens, there was little adjustment change when looking at an object behind due to the extension of the depth of field.