EEVblog 1554 - Optometrist AutoRefractor Keratometer TEARDOWN!

[EEVblog]

A teardown of a very interesting bit of optometry kit, a Shin Nippon NVISION K-5001 RefKeratometer (Auto Refractor Keratometer).
It can measure the curvature of your cornea, and well as refractive error to diagnose near and far sightedness.

Links:
https://www.rexxam.co.jp/themes/eye-care/products/images/nvk5001/NvisionK5001.pdf
https://www.academia.edu/59315264/Clinical_Evaluation_of_the_Shin_Nippon_NVision_K_5001_Grand_Seiko_WR_5100K_Autorefractor
https://www.opticsforhire.com/blog/keratometer-optical-design/
Manual: https://www.yumpu.com/en/document/read/25018677/english-manual

00:00 - What is an AutoRefractor Keratometer?
03:41 - Don't try this at home kids! Can Dave measure his eyeball?
06:17 - Teardown
08:14 - Pupil distance measurement
09:43 - Should have read the manual...
11:22 - How the Keratometer mire circle is generated
13:42 - Optical path and lenses
15:47 - The camera
16:53 - Fine auto-focus mechanism
18:22 - Main PCB