Standard window insect screens block 30-40% of the daylight coming through your window. They also restrict airflow. From the street, they make the windows look darker.

Window
Many window manufacturers offer “high transparency” window screens which utilize a thinner mesh material which is nearly invisible from the street and which allows much more light into your rooms. Of course, if you’re not going to open your windows (say, during the winter in cold climates) you can simply remove the screens. But for most of us, paying a little more for the high transparency screens is a much better option.

Resource links

Pella Window Screens