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This column is often, but not always, about ophthalmic tech. This is one of those ‘not always’ editions. Time to share some interesting or useful things from the internet which can help in a number of ways, from preparing presentations and taking surveys to interesting sites for your downtime. You will likely know some of them, but hopefully you may find one or two useful to your life right now.


Safe and easy to use QR code generator

QRCode Monkey is a free and easy to use QR code generator. Lots of styles are available and logos can be added. All the basic functionality is included without cost. I used the tool to generate all the QR codes for this article. Be careful when scanning the QR codes on this page, as there are plenty here. Your phone may lock on the first one it sees, so you may need to be creative when concealing the others from its view.

152 Visual Phenomena & OpticalIllusions



This website demonstrates and explains a vast array of static and animated optical illusions – I can’t imagine a more comprehensive library of this nature exists. The first one, ‘Stepping Feet’, and ‘Silencing by Motion’ are two of my favourites, but there are many to explore. The figure above shows ‘Blur & figure-ground reversal’. Difficult to read when clear but try blurring it by squinting your eyes (layman squint, not ophthalmic meaning).

Two great science YouTube channels

If you have never watched any of Steve Mould or Derek Muller’s (Veritasium) YouTube videos, you really should. Both content creators have released over 100 high-quality and interesting science explainer videos.

Very quick and easy polls

Minipoll is a speedy way to create a simple poll. No account or login is required. Good for quickly gathering opinions on date consensus. If all your participants are already in a WhatsApp group, I would just use the WhatsApp poll feature, but if you want to share a quick poll via an email, this site offers an effective way to do so.

File converter

If you ever need to convert a file from one type to another, this is a free, safe, and powerful tool that should help. Light use of the service is free, and I highly recommend it. I have used it several times over the last few years.

8MB Video

This site will compress any video down to 8MB in size. Other sizes are supported (like 25MB). I have found this of most use when I want to email a video. As videos are typically large, email is often not possible, and a file sharing service needs to be used. provides an easy way to trim a video down to size. Options are provided to mute sound and trim the video. Occasionally useful.


This site provides a range of themed illustrations to support projects and presentations. A vast range of concepts are available, and the colours can be easily altered. The illustrations are free to use, although the site requests you to provide attribution. Well built, and the illustrations are professional and high quality.


This is a web-based graphics editor. If you ever need to alter, create, or convert images, this is a free (ad-supported) tool that can be used without an account and with no installation. It is not as advanced as solutions like Photoshop, but it is still fully featured and easy to use.


If you need some advanced PDF features like editing, annotating, or filling PDF forms, give the free online version of PDFescape a look. No account or download is needed, so very safe, quick and easy.

AI image creation

An increasing array of AI image-creation tools are popping up. Nightcafe amalgamates most of the main ones into a single site and provides a rich interface to access them. Light usage is free of charge.

Royalty free images

If you want royalty free photographic imagery to support projects and presentations, try Unsplash or Pexels. Both have extensive libraries of images that can be used without payment or attribution.

Background noise

A Soft Murmur is an online background noise generator. When I’m working from home, I load it up in a tab and turn on a bit of ‘Coffee shop’, ‘Rain’ and ‘Thunder’. If you prefer crickets, fire or birdsong it is also worth a look. Also available as a mobile app.


This one is an app (Android or iOS) only. It is a good service to recommend TV shows. Tell the app which services you have access to (e.g. Netflix, Amazon Prime Video, etc.) and then tell it which shows you have enjoyed in the past. It will create a watch-worthy list for you.


The author has no proprietary or financial interests in the products discussed.




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David Haider

Bolton NHS Foundation Trust, Royal Bolton Hospital, UK.

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