I have been given a visual acuity, but what can my child actually see?

Sometimes, after an eye examination with an optometrist or ophthalmologist, you may receive a report containing a visual acuity. In a previous blog post I discussed how visual acuity is written, and what the numbers relate to, but what does it actually mean in terms of function? What can you see if your visual acuity is 6/24, for example?

Let’s think about some everyday tasks. What about recognising someone you know? Below is a clear image of a face.

Image: a girl faces the camera with a neutral facial expression.  She has reddish hair in a bob-cut.  She is standing against a backdrop of hills and a body of water, the background is out of focus.

This is how someone with a normal visual acuity would see a face. The features are clear and you could recognise the person if it was someone you knew. You can easily pick out their facial expression.

Now lets see what it looks like if you are visually impaired.

Image: the same image as above, of a girl with neutral facial expression, but this time, the facial features are slightly blurred

The above image is an approximation of what someone with a mild visual impairment might see; that is, an acuity of around 6/18. The images is less distinct, and it would be difficult to pick out subtle changes, but mostly, you can distinguish the facial features. Remember, this is for someone who is standing quite close to you.

For someone with moderate vision impairment, an acuity of around 6/24, it would look something like this:

Image: the same image as above, of a girl with neutral facial expression, but this time, the facial features are more blurred

At this level, it’s getting hard to distinguish the more subtle facial features, and if someone had a similar outline/profile, you could potentially mistake them. Again, bear in mind, that the person in the image is quite close; if we were trying to distinguish them from across a room, it would be very easy to mistake them for someone else.

Finally, lets look at how it might look for someone with severe vision impairment, that’s an acuity of around 6/60:

Image: the same image as above, of a girl with neutral facial expression, but facial features are only grossly visible due to the level of blur

At this level, facial features are not accessible. A person with this level of vision would be relying on other cues, such as voice, clothing, and context, to identify the person.

In Australia, people with visual acuity of worse than 6/60 are considered ‘legally blind’. It’s important to note that most people who are legally blind can still see some things, as illustrated above, it’s just that their vision is reduced enough that it is not considered useful in everyday life; they will need to use alternative ways to identify people, read, and get around safely.

This blog has provided just a single example of distinguishing a face, to demonstrate the impact of reduced visual acuity. But in every daylife, there are many, many other situations which are affected by vision levels. Consider, finding your food on your dinner plate, finding a toy in the toy box, or your door key wherever you last left it. What about telling whether the bus approaching is the one you are waiting for, or locating the toilets in an unfamiliar place?

For some more real-life simulations of reduced acuity, Next Sense have a Visual acuity simulations e-book that can be purchased for just a few dollars. If you are supporting someone with low vision, this can be a fantastic way to demonstrate to others involved in their care, how their vision impairment can impact on everyday tasks.