LED LIGHT SOURCE: It uses energy-saving LED constant light source, which emits light evenly without flickering, has a service life of more than 50,000 hours and is maintenance-free. It is not easy to cause visual fatigue even after long-term use, ensuring the accuracy of vision testing MULTI-FUNCTIONAL VISUAL TEST: This eye chart light box is a standard chart for measuring vision and detecting other vision problems; for example: astigmatism, myopia, hyperopia, color vision abnormalities, etc. SELECTED MATERIALS: Our LED eye chart light box uses acrylic panels, which are impact-resistant and shatter-resistant, and are matched with aluminum alloy frames to strengthen the overall structure. The font is processed by silk-screen printing technology, and the text is sharp, clear, and does not fade. It is still clearly visible after long-term use EASY TO INSTALL: This eye chart uses a back hook design for quick wall mounting. It can be used as a professional vision testing tool or as a modern style wall decoration. It is suitable for a variety of scenarios such as clinics, schools and homes Service: We place great emphasis on our customers' shopping experience. If you have any questions, please feel free to contact us; we will respond to you within 24 hours!