Why have I been mixing up words so much lately?

Stress can do that to you.

Have you had an eye exam recently? Maybe you should get your vision checked.
Have you started using a new device for reading emails? Maybe you need to adjust the display.

@Zissou It’s all things, not just emails.
Yes. I have to go back again they said that the nerve connecting my left eye to my brain is pale?

Are you using anything that might affect your sensory perception or your mental processes?

Like drugs? No.

Could be lack of sleep. That can do me in.

Anxiety;
Distraction/caused or not for many time reading;
Reading faster/caused for reasons on your current actual;

It is necessary to know since when the symptoms appear.
Your cause really doesn’t seem something to worry about, in a psychological way. — but it may be organic.

I don’t have any idea of the ophthalmology answer for it.

Try not to worry. I do it all the time and I have to do a double take, then I get a good laugh at myself. Some of the stuff I think I’m reading is funny as hell. :)

@Dutchess_lll – I sometimes get that same effect listening to people in noisy environments.

My wild guess (based only upon stuff I’ve read or heard about over (many) years, i.e., this is NOT my field at all(!), so yeah, likely utterly and completely wrong) would be a (probably benign) brain tumor.