title: Comparative effect of lens care solutions on blink rate, ocular discomfort and visual performance.
abstract: OBJECTIVE
  To help maintain clear vision and ocular surface health, eye blinks occur to distribute natural tears over the ocular surface, especially the corneal surface. Contact lens wearers may suffer from poor vision and dry eye symptoms due to difficulty in lens surface wetting and reduced tear production. Sustained viewing of a computer screen reduces eye blinks and exacerbates such difficulties. The present study evaluated the wetting effect of lens care solutions (LCSs) on blink rate, dry eye symptoms, and vision performance.
  
  
  METHODS
  Sixty-five adult habitual soft contact lens wearers were recruited to adapt to different LCSs (Opti-free, ReNu, and ClearCare) in a cross-over design. Blink rate in pictorial viewing and reading (measured with an eyetracker), dry eye symptoms (measured with the Ocular Surface Disease Index questionnaire), and visual discrimination (identifying tumbling E) immediately before and after eye blinks were measured after 2 weeks of adaption to LCS. Repeated measures anova and mixed model ancova were conducted to evaluate effects of LCS on blink rate, symptom score, and discrimination accuracy.
  
  
  RESULTS
  Opti-Free resulted in lower dry eye symptoms (p = 0.018) than ClearCare, and lower spontaneous blink rate (measured in picture viewing) than ClearCare (p = 0.014) and ReNu (p = 0.041). In reading, blink rate was higher for ClearCare compared to ReNu (p = 0.026) and control (p = 0.024). Visual discrimination time was longer for the control (daily disposable lens) than for Opti-Free (p = 0.007), ReNu (p = 0.009), and ClearCare (0.013) immediately before the blink.
  
  
  CONCLUSIONS
  LCSs differently affected blink rate, subjective dry eye symptoms, and visual discrimination speed. Those with wetting agents led to significantly fewer eye blinks while affording better ocular comfort for contact lens wearers, compared to that without. LCSs with wetting agents also resulted in better visual performance compared to wearing daily disposable contact lenses. These presumably are because of improved tear film quality.
authors: Vision Performance Institute, Pacific University College of Optometry, Forest Grove, USA. shunnan.yang@pacificu.edu
authors: Shun-nan
authors: SN
authors: Yang
authors: Yu-chi
authors: YC
authors: Tai
authors: James E
authors: JE
authors: Sheedy
authors: Beth
authors: B
authors: Kinoshita
authors: Matthew
authors: M
authors: Lampa
authors: Jami R
authors: JR
authors: Kern
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001767:Blinking / Q000187:drug effects*; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic; D018592:Cross-Over Studies; D015352:Dry Eye Syndromes / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011932:Reading; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014796:Visual Perception / Q000187:drug effects*; D055815:Young Adult
chemical_list: D018639:Contact Lens Solutions