When I take off my glasses/contacts to try active focus, I have to hold the paper/screen about 5 inches from my face. My eyes cross. I cannot look and focus with both eyes open. How do you do active focus with that?
Please don’t do this! I would say watch this, for starters: Differentials - YouTube
Wear differentials = enough corrections for close-up to be able to focus on things at least at an arm’s length away.
The Wiki summarizes the basic concepts.
Also if you haven’t read the 7-day guide yet, I recommend signing up for it. It’s free and you don’t need to buy anything after reading the 7 e-mails. You’ll have everything to kick off your EM journey correctly.
Thank you. I just completed the 7-day guide. I feel like I have a lot of information but am lacking the actual “what does this look like in practice.” I did get differentials for close work. Is that all I do? I feel like I’ve missed something along the way or something isn’t clicking.
When I started I could only see about 20cm (I’m up to 35cm now). That was the minimum where I could feel comfortable looking with both eyes. That’s about 8 inches. Five is just too close, you’ll need some minus lenses to push that out.
However, once you get past 8 inches/20cm, naked eye is awesome for active focus practice with a phone. My journey from 20cm to 35cm was greatly assisted by hours on the phone naked eye. I love the irony. The phone, that has helped us get so nearsighted, helping me undo some of that
Can you buy minus glasses locally? I’ve never seen them when I’ve looked for reading glasses.
In the US, Zenni’s sell good quality glasses for cheap, and you input the prescription. I’ve ordered at least two dozen glasses from them, averaging $15-20 each, and they’re every bit as good as the $400 glasses I used to get.
Just get the cheap lens material (1.5 refraction index I believe), with cheap frames, and get standard anti-reflection coatings.
A great resource for the aspiring EMer
As shared in my video linked above differentials are a very important step for all the reasons I listed, the 7 day email give you a foundation but there is still a fair amount to learn, keep looking around, My channel is full of tips and tricks, there are other students with channels, there is the whole blog and there is the wiki too.
@dianafil a bit of addition to @Hoofjr’ comment for you:
Zenni is in the US but they ship worldwide. “Input the prescription” means that you select the parameters from a drop down window, no requirement to provide scanned copy of the opto prescription. You can provide your requirements based on your own measurements.
There are other similar companies in almost every country, but Zenni is the most tested one I would say. Cheapest pair of glasses (frame + lenses with 1.5 index) starting from $15-20 plus shipping cost.
Thank you! Seems like a great site. However, I somehow need to find the “pupillary distance.” Going to call my optometrist and see if they have that information…
It’s pretty easy to measure it yourself with a ruler, but easier still to have someone tell you the answer if they already measured it for you. The average “PD” is around 64 mm.
Best if the number comes from the opto. However, they just like to keep it with themselves. To make it the last reason why you’d still order glasses from them for $400 instead of ordering from Zenni for $15-20.
There are several webpages where you can measure your PD by enabling the camera and holding a credit card sized card above your eyes (I avoid using actual credit cards just to be on the safe side)
If you have the option to leave PD blank when placing the order then it may be useful to know that most companies use a default PD around 63mms that I find way too wide…
Some online measuring webpages for smart phones: