pui theng yong, zainora mohammed, norliza mohamad fadzil, mohd harimi abd rahman, mohd izzuddin hairol, sharanjeet-kaur, sumithira narayanasamy.  (2024).  does the optimal level of illumination improve both visual functions and visual comfort in schoolchildren with low vision?.  - plos one.  1 - 18. 

mariah asem, sumithira narayanasamy, mahadir ahmad, masne kadar, mohd izzuddin hairol.  (2023).  association between visual perception and socioeconomic status in malaysian preschool children: results from the test of visual perceptual skills-4.  - children.  1-11. 

mohd izzuddin hairol, mahadir ahmad, muhammad aminuddin muhammad zihni, nur fatin syazana saidon, naufal nordin, masne kadar.  (2023).  the impact of school closures during covid-19 lockdown on visual-motor integration and block design performance: a comparison of two cohorts of preschool children.  - children.  1-12. 

mohd izzuddin hairol, yun rou lee.  (2022).  accuracy of vertical cup-to-disc ratio discrimination among clinical optometry trainees with different years of clinical experience.  - plos one.  1-11. 

mohd izzuddin hairol, naufal nordin, jacqueline png, sharanjeet-kaur, sumithira narayanasamy, manisah mohd-ali, mahadir ahmad & masne kadar.  (2021).  association between reduced visual-motor integration performance and socioeconomic factors among preschool children in malaysia: a cross-sectional study.  - plos one.  1-16. 

mohd izzuddin hairol, shaari ahmad, sharanjeet kaur, lei hum wee, fauziah abdullah, and mahadir ahmad.  (2021).  incidence and predictors of postpartum depression among postpartum mothers in kuala lumpur, malaysia: a cross-sectional study.  - plos one.  1-12. 

pui theng yong, norlaili arif, sharanjeet kaur, mohd izzuddin hairol.  (2020).  double eyelid tape wear affects anterior ocular health among young adult women with single eyelids.  - international journal of environmental research and public health.  1-14. 

sarah j waugh, monika f formankiewicz, m izzuddin hairol.  (2014).  effects of stimulus duration on foveal crowding using visual acuity letters.  - journal of vision.  787. 

mohd izzuddin hairol, norazizah abd latif, pui juan woi, nurul hafizah ahmad rashaidi, sharanjeet kaur, sarah j waugh.  (2014).  visual acuity and spatial interaction zones: investigating the periphery in anisometropic amblyopia.  - journal of vision.  772. 

hairol, m.i., formankiewicz, m.a., waugh, s.j..  (2013).  foveal visual acuity is worse and shows stronger contour interaction effects for contrast-modulated than luminance-modulated cs.  - visual neuroscience.  30(3):105-120 . 

sarah j waugh, monika a formankiewicz, m izzuddin hairol.  (2012).  contour interaction extents (in mar) for differently-sized cs vary little within, but lots between, lm and cm acuity systems.  - journal of vision.  12(10):101.