Holographic Technology & Vision Simulator
Holographic display is the only technology that can offer true 3D with all the required depth cues. Holographic head-worn displays (HWD) can provide continuous depth planes with the correct stereoscopic disparity for a comfortable 3D experience.
Existing HWD approaches have small field-of-view (FOV) and small exit pupil size, which are limited by the spatial light modulator (SLM).
Conventional holographic HWDs are limited to about 20° × 11° FOV using a 4 K SLM panel and have fixed FOV.
A holographic vision simulator device designed for patients with cataracts will allow them to experience preoperatively the best-corrected vision that can be obtained after the cataract extraction.
Technologies such as retinoscopy, aberrometry, optical coherence tomography, and biometry are available for diagnosing cataracts; however, their performance preoperatively cannot predict the postoperative visual acuity, they cannot correct aberrations, and they are limited to static pinhole exit pupils.
“Holography is considered the ultimate display technology that can offer natural 3-dimensional vision with all required focus and depth cues,” said Koray Kavakli, MS, a student, and Hakan Urey, PhD, a professor of electrical engineering, both from the Department of Electrical Engineering and the Translational Medicine Research Center at Koc University in Istanbul, Turkey.
Holography, Kavakli pointed out, is the only technology that can digitally control the phase, size, and shape of a light beam entering the pupil. In this study, the 10 patients with varying degrees of cataracts underwent ocular examinations before the simulator was tested.
They wore the holographic vision simulator on their heads during the experiments. The holographic screens detect solid noncataractous areas in millimeter-level accuracy on the crystalline lens by directing a light beam that shapes the exit pupil by using the pupil tracking.
The simulated vision the patients achieve, said Kavakli, facilitates their choice of different IOL options offered preoperatively and correction of any refractive errors. Results “All patients had better visual acuity when tested in our holographic simulator compared to the conventional eye examination,” Kavakli said.
“Patients without retina diseases exhibited 20/40 vision, whereas the patients with age-related macular degeneration or glaucoma had 20/70 vision.” Based on the results, the investigators concluded that the vision simulator can predict the patients’ postoperative visual acuity before they undergo cataract surgery.
“Our augmented-reality display device overperforms the existing vision simulators,” they commented. “This device also can be used for matching the right patient to the right choice of intraocular lenses, such as trifocal, monofocal, or extended depth-of-focus IOLs.”
The investigators also noted that the technology can be used with corneal diseases such as keratoconus that cannot be corrected with contact lenses and require surgery.