BLOOD VESSELS IN FRONT OF THE RETINA.
"…Blood vessels that sprawl across the retina's inner surface casting undesirable shadows onto the retina." pg,68 Emphasis added. He also calls the shadows "unwanted" pg.69. Note the emotional language "sprawl", "undesirable" and "unwanted".
Now let's ask some questions. How much trouble do these shadows cause you? If you're eyes are working the way they were designed they don't cause any trouble at all. This means there is more engineering design to uncover. There are several scientific design questions we should ask.
1. What are the blood vessels doing, i.e. are they needed?
2. Are there any design features that compensate for and enhance the image quality?
3. How much do the blood vessels degrade the image quality?
4. How does the redesigned eye work when these blood vessels are removed or relocated through genetic changes in the reproductive cells?
The fact is that the blood vessels supply needed nutrients to the cells, so if they need to be there a designer would compensate for this and devise ways to filter out the shadows. It is correct that the shadows are undesirable and that's why they have been intelligently designed out of your vision. There are several amazing design features that compensate for the undesirable shadows.