A diagnostic device for use in performing refractive errors assessment and neurodegenerative disorders screening is described herein. The diagnostic device includes a display configure to render dynamically adjusted, dichoptic visual stimuli to a user, a varifocal optics system orientated between the display and the user's eyes, an ocular reflex analyzer emitting light signals towards the user's eye s and obtaining light signal reflected from selected part of the eye to measure eye accommodation during an on-going visual stimulation, and an eye tracking system configured to track movement of the user's eyes.