there are many methods to check vision according to the age of the patient. it is different for preverbal or verbal children and for adults. many types of vision charts available. snellen chart is one of them. there are etdrs chart early treatment diabetic retinopathy study) keeler logmar chart bailey-lovie chart etc. for lazy eye usually crowded charts are preferred with more letters in one row like etdrs chart. then some other tests are also done like color vision stereopsis (depth perception) near vision refraction for best corrected visual acuity and complete eye examination to rule out any cause of decreased vision in lazy eye. you need a full eye examination. your eye doctor will do accordingly and then advise appropriate treatment. for further information consult an eye care ophthalmologist online --><link>
how will the doctor identify my lazy eye vision percentage?