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Eye and Vision Care

Black Letters Turn Green



My 12 year old son, suddenly started laughing while reading his book in the car because the letters had all turned green. He turned all of the pages and he saw all of the letters as green. A bright light green he described. Then they all turned to black again. It happened a couple of times within an hour and he thinks it is soooo cool... could there be a problem??? His vision does not seem to be bothered and he says he sees fine!


The green color perception could occur if he happened to be looking at something that was the color red and then looked at a book and the page or letters looked green. This can occur due to color opponency, which is a visual perceptual phenomenon.

I would not be too concerned about the health of his eyes unless he continues to notice these changes and/or there is associated loss of vision.

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Response by:

Aaron  Zimmerman, OD, MS Aaron Zimmerman, OD, MS
Clinical Associate Professor of Optometry
College of Optometry
The Ohio State University