Vitreous Floaters: The patient's symptoms of a black spot in the middle of the left eye, especially after crying, could be due to vitreous floaters. Floaters are common and can be more noticeable when people are emotionally upset or crying, as the vitreous humor can become more pronounced.

Retinal Tear or Detachment: Although less common, a retinal tear or detachment could present with sudden onset of floaters, especially if the patient has experienced recent trauma or has a history of retinal issues. The patient's vision is 20/25, which might not immediately suggest a severe retinal issue, but it's still a possibility.
Migraine: Ocular migraines can cause visual disturbances, including seeing spots or auras. The emotional distress from the death of a family member could trigger a migraine.

Retinal Vein Occlusion: This condition can cause sudden vision changes, including floaters, and is more common in older adults but can occur at any age. It's crucial to rule out due to its potential for severe vision loss.
Central Serous Chorioretinopathy (CSC): CSC can cause sudden vision changes, including a gray film or spot, especially in one eye. It's more common in young to middle-aged adults and can be associated with stress.
Posterior Vitreous Detachment (PVD): While often benign, PVD can cause sudden onset of floaters and is a common condition that increases with age.

Ocular Melanoma: Although rare, ocular melanoma can cause visual disturbances, including seeing spots or flashes of light. It's essential to consider in the differential diagnosis, especially if other symptoms or risk factors are present.
Sympathetic Ophthalmia: This is a rare, inflammatory condition that can occur after eye trauma or surgery, leading to vision changes in the unaffected eye. Given the patient's recent emotional distress and lack of reported trauma, this is less likely but should be considered if other symptoms arise.