This prospective study investigated the validity and test-retest reliability of stereopsis test using head-mount display (HMD). Contour-based circles (crossed disparity: 1,960 to 195 arc of seconds(arc secs)) were generated as separate images on a high resolution phone display (Galaxy S7; Samsung, Suwon, Korea) using a HMD (Galaxy Gear VR; Samsung, Suwon, Korea). Two images were independently projected to each eye as graded circles with random dot background. While the position of the stimulus changed from among 3 possible locations, the subjects were instructed to select the circle with disparity by pressing the corresponding position on a keypad. The results of the new HMD stereotest were compared to those from standard Randot and TNO stereotests.

Inclusion Criteria:

1. The subjects who want or need to visual acuity test or to test for a prescription for glasses visited the hospital. 2. The Subjects' ages ranged from 19 to 60 years in the study.

Exclusion Criteria:

1. Ocular alignment was assessed with cover-uncover and alternate prism cover testing at distance and near. Significant exodeviation included exophoria was considered to be ≥6 prism diopters were excluded.
2. Subjects with a history of ocular surgery within 3 months of the study were excluded.
3. Foreigners or subjects who are unable to understand informed consent were excluded.
4. Subjects with a history of eye problems, including infection, inflammation, cataract, vitreous opacity or retinal diseases were excluded.
5. Subjects with corrected visual acuity of 20/32 in bad eye were excluded.
6. Subjects with significant refractive error considered to be ≥2.00 diopters of anisometropia were excluded.
7. A female who is pregnant, may be pregnant, or is lactating was excluded.

normal healthy volunteers