[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.54,0:00:02.94,Default,,0000,0000,0000,,In this video, I wanted to show you how to use the lensometer. 
Dialogue: 0,0:00:03.09,0:00:05.94,Default,,0000,0000,0000,,The lensometer is a device used for checking prescription glasses
Dialogue: 0,0:00:05.94,0:00:07.11,Default,,0000,0000,0000,,and can be a little confusing. 
Dialogue: 0,0:00:07.47,0:00:08.73,Default,,0000,0000,0000,,The first step is, of course, to put 
Dialogue: 0,0:00:08.73,0:00:09.90,Default,,0000,0000,0000,,the glasses in the frames here, 
Dialogue: 0,0:00:09.90,0:00:11.82,Default,,0000,0000,0000,,and you can see this platform moves up and down. 
Dialogue: 0,0:00:12.27,0:00:15.39,Default,,0000,0000,0000,,And you want to put the optical center of this lens 
Dialogue: 0,0:00:15.57,0:00:17.82,Default,,0000,0000,0000,,such that it aligns here, 
Dialogue: 0,0:00:17.97,0:00:20.79,Default,,0000,0000,0000,,and this little brace holds the glasses in place. 
Dialogue: 0,0:00:20.79,0:00:22.56,Default,,0000,0000,0000,,You want to make sure both glasses 
Dialogue: 0,0:00:22.68,0:00:25.44,Default,,0000,0000,0000,,are touching the bottom of this platform. 
Dialogue: 0,0:00:25.80,0:00:29.37,Default,,0000,0000,0000,,Turn it on, and then look through this eye piece, 
Dialogue: 0,0:00:29.37,0:00:30.51,Default,,0000,0000,0000,,and this is what you should see. 
Dialogue: 0,0:00:30.99,0:00:33.06,Default,,0000,0000,0000,,Now, the hard part with using this machine 
Dialogue: 0,0:00:33.06,0:00:34.92,Default,,0000,0000,0000,,is you have to use two dials at the same time. 
Dialogue: 0,0:00:35.28,0:00:36.78,Default,,0000,0000,0000,,There's an axis dial up here 
Dialogue: 0,0:00:37.26,0:00:39.72,Default,,0000,0000,0000,,and there is a focus dial down here. 
Dialogue: 0,0:00:39.72,0:00:41.49,Default,,0000,0000,0000,,And you spin both of these and the goal 
Dialogue: 0,0:00:41.49,0:00:43.17,Default,,0000,0000,0000,,is to get the three small lines-- 
Dialogue: 0,0:00:43.17,0:00:44.91,Default,,0000,0000,0000,,the three little lines-- next to each other, 
Dialogue: 0,0:00:45.18,0:00:46.86,Default,,0000,0000,0000,,lined up and in focus. 
Dialogue: 0,0:00:48.03,0:00:50.43,Default,,0000,0000,0000,,So if we zoom in, we can see that there's three lines. 
Dialogue: 0,0:00:50.64,0:00:53.28,Default,,0000,0000,0000,,You want to get them lined up and in focus. 
Dialogue: 0,0:00:53.49,0:00:55.92,Default,,0000,0000,0000,,And then you can mark down what this is. 
Dialogue: 0,0:00:55.92,0:00:57.54,Default,,0000,0000,0000,,So if you look on our dial here and our focus, 
Dialogue: 0,0:00:57.54,0:01:00.63,Default,,0000,0000,0000,,we can see this is a 3.25 so that's the sphere. 
Dialogue: 0,0:01:00.66,0:01:02.19,Default,,0000,0000,0000,,The sphere is 3.25. 
Dialogue: 0,0:01:02.70,0:01:07.05,Default,,0000,0000,0000,,Now you move the focus in whatever direction it takes 
Dialogue: 0,0:01:07.26,0:01:09.63,Default,,0000,0000,0000,,in order to get the three fat lines in focus. 
Dialogue: 0,0:01:09.66,0:01:12.30,Default,,0000,0000,0000,,And the difference between those is your cylinder power. 
Dialogue: 0,0:01:12.30,0:01:15.33,Default,,0000,0000,0000,,So we went up +2.75 to get to 6.0. 
Dialogue: 0,0:01:15.36,0:01:17.52,Default,,0000,0000,0000,,So that's our cylinder +2.75.
Dialogue: 0,0:01:17.88,0:01:19.98,Default,,0000,0000,0000,,Our axis looks like it's about 12 degrees. 
Dialogue: 0,0:01:20.31,0:01:21.66,Default,,0000,0000,0000,,So here is our prescription. 
Dialogue: 0,0:01:22.77,0:01:25.08,Default,,0000,0000,0000,,Now, to get the bifocal power, 
Dialogue: 0,0:01:25.08,0:01:27.39,Default,,0000,0000,0000,,I need to move the glasses up to the bifocal segment 
Dialogue: 0,0:01:27.60,0:01:29.28,Default,,0000,0000,0000,,and see how much you need to change it 
Dialogue: 0,0:01:29.40,0:01:31.83,Default,,0000,0000,0000,,to get the three fat lines in focus again. 
Dialogue: 0,0:01:32.04,0:01:35.58,Default,,0000,0000,0000,,So we went from +6.0 to +8.5,
Dialogue: 0,0:01:35.73,0:01:37.92,Default,,0000,0000,0000,, so our add is +2.50.