Corneal Abrasion or Foreign Body: The patient's history of polishing rocks and feeling like something got in his eye 10 days ago, along with the lack of relief from washing at home, makes this the most likely diagnosis. The cornea can be easily scratched or a small foreign body like a rock particle can become lodged, causing persistent discomfort and foreign body sensation.

Conjunctivitis: This could be either allergic or infectious, potentially caused by the introduction of a foreign substance into the eye while polishing rocks. Symptoms can include redness, itching, and a sensation of something in the eye.
Dry Eye Syndrome: Prolonged irritation or improper washing technique could lead to dry eye, exacerbating the sensation of having something in the eye.
Blepharitis: Inflammation of the eyelids can cause irritation and a foreign body sensation, possibly due to the introduction of debris while working with rocks.

Corneal Ulcer: Although less likely, a corneal ulcer could develop from an untreated corneal abrasion or foreign body, especially if the patient has been rubbing his eyes or using contaminated water for washing. This is a serious condition that can lead to vision loss if not promptly treated.
Endophthalmitis: This is a severe inflammation of the interior of the eye, usually caused by infection. It's a rare but potentially devastating complication of a penetrating eye injury, which could occur if a rock particle penetrated the eye.

Arc Eye (Photokeratitis): If the patient was polishing rocks without proper eye protection and was exposed to UV radiation from his tools, he could be experiencing arc eye, which is an inflammation of the cornea caused by UV exposure.
Ocular Tumors: Though extremely rare and unlikely to present with a sudden onset of foreign body sensation, ocular tumors could cause a variety of symptoms including discomfort and unusual sensations in the eye.