Visual acuity examination application for children with strabismus/low vision amblyopia “Low Age Low Vision Threshold Visual Acuity Checklist”. The Low Vision Threshold Vision Checklist was invented by Professor Liu Dongguang, a renowned amblyopia expert, graduate student of Sun Yat-sen University Eye Center and recipient of more than 40 national patents. It is specially designed for “threshold visual acuity” examination and treatment follow-up of children with strabismus or other low vision. The test results can be used to guide the development of high-precision individualized treatment plans for children with low vision. Therefore, every post-strabismus child should learn to recognize this chart as soon as possible to find out the threshold visual acuity in order to improve their vision more effectively. Parents should understand that surgery is the first step in treating strabismus; it only solves the strabismus problem and does not functionally improve visual acuity or solve the binocular monovision problem, which is the ultimate goal of strabismus treatment. Therefore, in order to help children regain useful vision above 0.5, parents must pay attention to vision enhancement treatment for severe amblyopia after surgery. Otherwise, even the most successful surgery can leave a lifetime of low vision or blindness. It is well known that children’s visual acuity after strabismus surgery is almost always below 0.1, and it is impossible to check the visual acuity with the ordinary visual acuity table whose maximum visual standard is 0.1,. Therefore, a targeted and highly refined vision rehabilitation program cannot be developed. For this reason, Professor Liu Dongguang invented a high-definition threshold visual acuity examination and treatment follow-up chart with a fineness of 0.02 or less, hoping to help children with low vision below 0.3 recover to a useful vision of 0.5 or more as soon as possible. There are several types of icons in the “Low Vision Threshold Vision Checklist”: 1. Threshold “e” or “c” icons: suitable for children over 4.5 years old 2. Icons: suitable for children aged 3.5-4.5 who can count their fingers 3. Threshold “stationery” and “animal” image icons: suitable for children aged 2.5-3.5 who can read these images 4. “image icon: suitable for children aged 1.5-2.5 who can recognize these images. Note: 1, threshold visual acuity: that is, threshold visual acuity, crossing this threshold, visual acuity will improve the level of visual acuity; 2, visual marker fineness, that is, the precision of the change in the size of the visual marker, but also the difficulty of improving visual acuity. The higher the fineness, equivalent to the smaller the stairs, the easier it is to climb up the vision, the