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In January, a controversial report claimed that people with autism have ‘eagle-eye’ vision. Now, four scientists have published rebuttals to that study, citing major flaws in the way the experiment was carried out.

In the original paper, Emma Ashwin used a computer program to measure how well people with autism can see super-small pictures. Controlled experiments of this kind hadn’t been done before, but there are many anecdotal stories of people with autism noticing tiny details of a scene (sometimes at the expense of seeing the ‘big picture’).

Ashwin’s experiment, published in Biological Psychiatry, found that adults with autism have off-the-charts scores of visual acuity: 2.79 — meaning they can resolve images at 2.79 times the distance of average adults — compared with 1.44 for the control group. She suggested that this super vision may stem from an unusually large number of densely packed eye cells.

These numbers are striking, but might be meaningless. Ashwin’s group mangled the settings of the computer program, says its creator, Michael Bach. In a letter to the editor of Biological Psychiatry, he lists many problems with the researchers’ setup. Most notably, participants sat too close to the computer screen. With the shorter distance, the program cannot accurately measure acuities larger than 1.44.

Another letter, submitted to the journal by two researchers from Swinburne University of Technology in Australia, chides the idea that people with autism have densely packed eye cells. Apparently, in hawks — known for their fantastic eyesight — better vision comes not from the density of retinal cells, but from bigger eyes.

Ashwin admits that technological problems could have affected her data. But she also defends her work by pointing out that inflated acuity values would be similar in all participants, and so couldn’t account for the large difference between the autism and control groups.

Of course, the only way to definitively resolve these issues is to repeat the experiments. Happily, Ashwin is doing just that — this time collaborating with Bach.