What indicates the need for patching in strabismus treatment?

Patching in the treatment of strabismus is typically indicated when there is a need to improve the visual acuity of the deviating eye, especially if the patient has amblyopia, often referred to as "lazy eye." This condition commonly occurs when there is unequal visual input from the two eyes due to misalignment.

When a child has unilateral eye deviation, the misaligned eye may not be effectively used for sight, leading to reduced vision. By patching the dominant eye, the treatment encourages the use of the weaker or misaligned eye, promoting visual development and potentially improving its function. This process helps to stimulate the neural pathways associated with the underused eye, ultimately enhancing its visual acuity over time.

The other options have different implications for strabismus treatment. Loss of vision in one eye and presence of double vision may be signs or effects resulting from strabismus rather than direct reasons for patching. Asymmetric corneal light reflexes can indicate strabismus but do not alone justify patching unless accompanied by factors leading to amblyopia. Thus, unilateral eye deviation serves as the most relevant indicator for patching in this context, as it aims to correct the potential visual deficit associated with the misalignment.