Final answer:
The lens is the part of the eye that could be damaged if someone is unable to focus an image on the retina.
Step-by-step explanation:
The part of the eye that could be damaged if your eyes are incapable of focusing an image on the retina is the lens. The lens is responsible for bending light rays and focusing them onto the retina. If the lens is damaged or unable to properly focus the light, it can result in blurry vision or difficulty processing what is being seen.