 Out of the five senses, the laws of vision creates the most devastating effect on the personal, family and society level. According to WHO, 80% of all blind are age 50 or above and 70% of blindness in developed countries is caused by long-term retinal diseases. A common feature of these diseases is the overgrowth of blood vessels in the back of the eye. The dawn of anti-vegetarian agents in the past decade is no short of a miracle. These protein drugs work like magic bullets to fight the unwanted blood vessels. The caveat is patients must receive monthly injections in order to maintain their vision. Once injection stops, blindness kicks in. Although inconvenient and painful, patients must consider themselves lucky if they could indeed receive injection after injection. A year of treatment on anti-fed HIV will cause a hefty price tag of $12,000. Now let's put this number in perspective. In emerging economies such as China, Brazil, India and Russia, the total healthcare expenditure per capita per year ranges from a few hundred to fifteen hundred US dollars. So the current therapy, although effective, is already too expensive for developed countries and sadly is unreachable for the world's majority. However, these back-of-the-eye diseases are far from being a rich man's problem because the aging of population that affects the developing and developed worlds alike are related with the rising prevalence of these diseases. Here is some statistics. China now has more than 30 million of age-related macular degeneration patients. The number will reach 50 million by 2050. Indonesia has more than one million patients who suffer from diabetes-related eye diseases. Here is yet another insurmountable obstacle for frequent injections. In less developed countries, the number of eye doctors serving a million populations is in a single digit or even lower sometimes. The doctors are usually located in urban areas, meaning very limited access by the rural population. So a paradigm shift in the treatment is necessary and a simple solution to all these problems may lie in a piece of gel. So my lab makes this gel using a polymer of sugars. So these materials are highly compatible with the eye as it resembles the jelly-like features that sits inside the eyeball. On the molecular level, the hydrogel is a network of interconnected polymer chains. To calculate the mesh size, my lab has developed a model inspired by the Nobel-winning Bloch theory that describes elegantly the behavior of overlapping polymer chains. So the very small mesh is able to resist the movement of protein drugs so they can sip out slowly and steadily over multiple months. That means one single protein gel depot can replace multiple injections. My lab has also engineered hydrogels to be injectable. The mixture containing the polymers and the protein drugs start out as a liquid. When they are injected into the eyeball and inside the eyeball, the polymer chains quickly lock with each other with a click reaction to form a solid gel. Longly, when the protein drug is injected to the eye, it is cleared rapidly and the concentration drops to a very low level. But with the hydrogel depot, the amount of protein drugs can be maintained within a therapeutic concentration window over a long time. My lab has recently reported that with careful design, the hydrogel depot could indeed reduce the growth of newly formed blood vessels in the eye. These pathological features are shown in the retina picture as bright spots. So we can see that one bolus injection after a month cannot reduce the bright spots. But with the gel, it can do so even after five months. So can the long term drug release be translated to long term therapeutic effect? Yes, and notice the amount of protein that is packed inside the gel is the same as that given in one injection. That means less drug is being wasted on clearance but more can stay and stay in the eye for a longer period of time. So the hydrogel technology promises to revolutionize the anti-fetched therapy for the eye. By dramatically reducing the cost of therapy and the demand of ophthalmologists, treatment can one day become affordable, accessible, and available. There's a Chinese prophet by Lougie saying that the highest good is like water. So hydrogel that entraps water may one day provide a solution for path forwards to safe eyesight for all.