While glaucoma is typically believed to affect peripheral vision, it does affect many patients’ ability to read. As glaucoma progresses, it creates a fog in your vision that starts in the peripheral but can reach into your central and mid-peripheral vision in some cases. Discover more about why glaucoma affects the ability to read, how a glaucoma patient’s reading ability compares to others, and how technology is helping glaucoma patients read.* 

Why does glaucoma affect reading?

A glaucoma patient’s ability to read may be affected by:

• Decreased contrast sensitivity (ability to distinguish objects from the background) due to the loss of retinal ganglion cells, which may occur at the earlier stages of glaucoma
• Disruption of the magnocellular visual pathway, which involves maintaining eye fixation and performing quick eye movements when reading 

How does glaucoma patients’ reading ability compare?

One study found glaucoma patients, even at earlier stages, read more slowly and with more errors than those without glaucoma. At the University of Turin in Italy, they grouped 140 participants into two classes: those with early- or moderate-stage primary open-angle glaucoma (POAG) and those without glaucoma. They tested and compared their reading ability with the Radner Reading Charts. 

Their findings showed:

• Reading speed was reduced by a mean of 27 words per minute in glaucoma participants, and the critical print size was larger than the print for controls. 
• In glaucoma participants, the average reading speed linearly decreased with the reduction of visual field and reading acuity.
• While visual acuity did not differ between the two groups, glaucoma patients did have more errors when reading.

What can be done to make reading easier?

For glaucoma patients, it is important to see an eye care professional regularly to help manage intraocular pressure (IOP) and prevent vision from worsening. Vision may still worsen in some cases, but there are still ways to help make reading easier, such as: 

• Increase the text size and/or screen brightness when working on the computer or other electronic devices. 
• Use spotlighting when reading a book. 
• Consider reading on a tablet or other device that enables reverse polarity (white letters on a black background instead of black letters on a white background).

More information on glaucoma and reading can be found on Your Sight Matters and Primary Care Optometry News on Healio.

*Ramulu, P. Y. (2020, Oct. 1). Glaucoma and Reading Ability. Glaucoma Research Foundation. https://www.glaucoma.org/glaucoma/glaucoma-and-reading-ability.php

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