Purpose: Despite the widespread practice of gradually adapting all new soft contact lens wearers (neophytes), there is little evidence-based research underpinning such practice. This work determined if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone-hydrogel daily disposable contact lenses. Method: At four sites, neophytes (19-32 years) were randomly assigned to an adaptation schedule: fast (10 hours wear from the first day) or gradual (4 hours on the first day, increasing their wear-time by 2 hours on each subsequent day until they had reached 10 hours) and hydrogel (n=24 fast; n=21 gradual) or silicone-hydrogel (n=10 fast; n=10 gradual) contact lenses. Masked investigators graded ocular surface physiology and non-invasive tear breakup-time (NIBUT). A range of subjective scores (using 0-100 visual analogue scales) were recorded at the initial visit and after 10 hours of lens wear, 4-6 days and 12-14 days after initial fitting. Subjective scores were also repeated after 7 days. Results: There was no difference (p>0.05) in ocular surface physiology between the fast and gradual adaptation groups at any time point in either lens type. NIBUT was similar at all time points for both adaptation groups in both lens types with the exception that the gradual adaptation silicone-hydrogel wearers had a slightly longer NIBUT (p=0.007) than the fast adaptation group. Subjective scores were also similar across the visits and lens types with the exception of 'lens awareness' and 'ease of lens removal' which were better (p<0.05) in the fast compared with the gradual adaptation hydrogel lens group at day 7. Additionally, 'end-ofday discomfort' was better (p=0.02) in the fast compared with the gradual adaptation hydrogel lens group at 12-14 days. Conclusion: There appears to be no benefit in soft contact lens adaptation for neophytes with modern contact lens materials.

Stimulation of the accommodation system results in a response in the vergence system via accommodative vergence cross-link interactions, and stimulation of the vergence system results in an accommodation response via vergence accommodation cross-link interactions. Cross-link interactions are necessary in order to ensure simultaneous responses in the accommodation and vergence systems. The crosslink interactions are represented most comprehensively by the response AC/A (accommodative vergence) and CA/C (vergence accommodation) ratios, although the stimulus AC/A ratio is measured clinically, and the stimulus CA/C ratio is seldom measured in clinical practice. The present study aims to quantify both stimulus and response AC/A and CA/C ratios in a binocularly normal population, and determine the relationship between them. 25 Subjects (mean ± SD age 21.0 ± 1.9 years) were recruited from the university population. A significant linear relationship was found between the stimulus and response ratios, for both AC/A (r² = 0.96, p < 0.001) and CA/C ratios (r² = 0.40, p < 0.05). Good agreement was found between the stimulus and response AC/A ratios (95% CI -0.06 to 0.24 MA/D). Stimulus and response CA/C ratios are linearly related. Stimulus CA/C ratios were higher than response ratios at low values, and lower than response ratios at high values (95% CI -0.46 to 0.42 D/MA). Agreement between stimulus and response CA/C ratios is poorer than that found for AC/A ratios due to increased variability in vergence responses when viewing the Gaussian blurred target. This study has shown that more work is needed to refine the methodology of CA/C ratio measurement.

To establish the optimum grading increment which ensured parity between practitioners while maximising clinical precision.Methods: Second year optometry students (n=127, 19.5 ± 1.4 years, 55% female) and qualified eye care practitioners (n=61, 40.2 ±14.8 years, 52% female) had 30 seconds to grade each of bulbar, limbal and palpebral hyperaemia of the upper lid of 4 patients imaged live with a digital slit lamp under 16x magnification, diffuse illumination, with the image projected on a screen. The patients were presented in a randomised sequence 3 times in succession, during which the graders used the Efron printed grading scale once to 0.1 precision, once to 0.5 precision and once to the nearest integer grade in a randomised order. Graders were masked to their previous responses.Results: For most grading conditions less than 20% of clinicians showed a ≤0.1 difference in grade from the mean. In contrast, more than 50% of the student graders and 40% of experienced graders showed a difference in grade from the mean within 0.5 for all conditions under measurement.Student precision in grading was better with both 0.1 and 0.5 grading precision than grading to the nearest unit, except for limbal hyperaemia where they performed more accurately with 0.5 unit precision grading. Limbal grading precision was not affected by grading step precision for experienced practitioners, but 0.1 and 0.5 grading precision were both better than 1.0 grading precision for bulbar hyperaemia and 0.1 grading precision was better than 0.5 grading precision and both were better than 1.0 grading precision for palpebral hyperaemia. Conclusion:Although narrower intervals scales maximise the ability to detect smaller clinical changes, the grading increment should not exceed one standard deviation of the discrepancy between measurements. Therefore, 0.5 grading increments are recommended for subjective anterior eye physiology grading (limbal, bulbar and palpebral redness).

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Hundreds of UK optometrists gathered in the Midlands last month for the College of Optometrists' annual conference, where a high profile keynote speaker reminded delegates that there is much more to vision than meets the eye.