Differential Diagnosis for Dark Spots When Covering One Eye
Single Most Likely Diagnosis
- Floaters: This is the most common cause of seeing dark spots when covering one eye. Floaters are small, shadowy spots that appear in the visual field due to the presence of tiny clumps or cells in the vitreous humor, the clear gel-like substance that fills the inside of the eye. They are more noticeable when looking at a bright, uniform field, such as the sky or a white wall, and can become more prominent when covering one eye due to the increased contrast.
Other Likely Diagnoses
- Vitreous Detachment: This condition occurs when the vitreous gel separates from the retina. It can cause the appearance of new floaters, which might be perceived as dark spots when covering one eye. Symptoms often include a sudden increase in floaters and flashes of light.
- Retinal Tears or Detachment: While more serious, these conditions can initially present with symptoms similar to floaters, including seeing dark spots or a shadow in the visual field. They are medical emergencies and require immediate attention.
Do Not Miss Diagnoses
- Retinal Migraine (Ocular Migraine): This condition can cause temporary visual disturbances, including seeing spots or shapes, but it is usually accompanied by headache and other migraine symptoms. Missing this diagnosis could lead to unnecessary worry but recognizing it can help in managing symptoms.
- Central Serous Chorioretinopathy (CSC): This condition involves the accumulation of fluid under the retina, leading to a detachment and potential visual disturbances, including blind spots or distorted vision. It's crucial to diagnose and treat to prevent permanent vision loss.
Rare Diagnoses
- Choroidal Melanoma: A rare type of eye cancer that can cause visual disturbances, including seeing dark spots, due to the tumor's growth in the choroid layer of the eye. Early detection is critical for effective treatment.
- Sympathetic Ophthalmia: A rare, inflammatory condition that can occur after trauma to one eye, leading to inflammation in the other eye. It can cause a variety of symptoms, including visual disturbances. Prompt recognition and treatment are necessary to preserve vision.