Use a blending stump or tissue, but don't overdo it, or the drawing will look "muddy."
The distance between the eyes is usually the width of one eye. The Five-Eye Rule: The head is typically five "eyes" wide. Secrets to Drawing Realistic Faces
💡 Treat the eye as a sphere. The eyelid has thickness and casts a tiny shadow on the eyeball. Use a blending stump or tissue, but don't
Ensure you have a true black and a bright white highlight. Use a blending stump or tissue