Common Branded Redeye

This was a very different butterfly for me..
All butterflies belonging to Hesperiidae family are either crepuscular, i.e. flying mainly at dawn and dusk; or are found in the depths of the forest where little sunlight penetrates even in the middle of the day. They therefore need particularly acute vision and high sensitivity in low light
In the eyes of all Hesperiidae the distance between the cones and rods, and the sensory cells behind them is greater than in other butterfly families. This allows more light to spill onto neighbouring rods, which increases resolution and sensitivity. In the case of the red-eyed genera the distance between the cones and rods is such that only certain wavelengths of light are reflected back to the observer.

This is nature's amazing engineering!!!!
Every living thing is different :-)