1. The angle of divergence between optical axes of the ommatidia (morphological visual acuity) ranges from 9° to 10°.

2. Acone definition is - having ommatidia that lack the crystalline cone of the lens system and that form the image by apposition.

3. The divergence angle between visual units as measured by these functional methods (10.3 °) is close to the anatomical entrance angle for the ommatidia (10.5 °).