Accurate and non-invasive methods for objectively identifying and monitoring head injuries (such as a concussion) are still an unmet need. It is known that pupil constriction in response to light stimuli can reflect changes in neural activity in the brain and is associated with sleep disturbances.

The investigators aim to examine the feasibility of using virtual reality goggles for monitoring traumatic brain injury by analyzing the pupillary response to multifocal chromatic stimuli. The VR device was programmed to present brief, low-intensity light stimuli (without glare), while the headset's camera records the pupil's reaction.

Healthy adults, patients with combat-related mild to moderate TBI and age- and gender-similar soldiers without TBI (defined as war-related injury who screen negative for TBI based on symptoms, blood, and/or head CT) will be recruited as non-TBI trauma (NTT) controls.

All subjects will undergo: A complete ophthalmologic examination to exclude ocular pathologies, including intraocular pressure (Goldmann applanation tonometry), and slit lamp biomicroscopy of the anterior and posterior segments; Assessment of best corrected visual acuity (BCVA); Color vision test, and VR Chromatic Pupilloperimetry (VRCP) testing.

Inclusion Criteria:

1. Male and female subjects
2. Clear ocular media a

TBI group:

1. Combat-related mild to moderate TBI
2. Have either elevated TBI-associated blood biomarkers (Abbott Allinity I, GFAP/ UCHL1) and/or initial trauma head CT positive for acute intracranial trauma

Non-TBI Trauma group:

1. Age- and gender-similar soldiers without TBI (defined as war-related injury who screen negative for TBI based on symptoms, blood, and/or head CT)

Exclusion Criteria:

1. Neuropsychiatric diseases
2. Any other neurodegenerative diseases
3. History of stroke, epilepsy, head trauma, or head tumors
4. Ocular disease or ocular surgery within the last six months

1. TBI group - soldiers with combat-related mild to moderate TBI (defined as blast TBI presenting Glasgow Coma Scale 13-15) and have either elevated TBI-associated blood biomarkers (Abbott Allinity I, GFAP/ UCHL1) and/or initial trauma head CT positive for acute intracranial trauma
2. Non-TBI trauma (NTT) group - Age- and gender-similar soldiers without TBI (defined as war-related injury who screen negative for TBI based on symptoms, blood, and/or head CT) .
3. Healthy volunteers - Age- and gender-similar to TBU group.