As i understand it we dyslexic people read more in blocks of words among other issues with order of letters and or sounds. Easily two words can become confused with each other if the look enough alike. Take defiantly and definitely, two words I often mistake for one another and often have trouble spelling individually. The dyslexic font has more spacing between letters which helps a ton.
If you want to know more about dyslexia
https://www.mayoclinic.org/diseases-conditions/dyslexia/symptoms-causes/syc-20353552
And here is some research related to dyslexia from the openDyslexic website