Article: Add 1 cup (200 g) of granulated sugar to a medium size saucepan with a heavy bottom. Turn the burner to medium to allow the sugar to start to heat. A 2 quart (1.9 L) saucepan is usually large for the sauce. Make sure that your saucepan is clean before your start making the sauce. If there is any dirt or debris in it, crystals can form around it when you begin heating the sugar. As the sugar is heating, use a heat-resistant rubber spatula or wooden spoon to stir it constantly. The sugar will start to clump, and eventually melt into a liquid. Continue stirring it until the liquid is thick and turns a dark amber color, which can take 5 to 10 minutes. The sugar can burn easily, so be sure to watch it and stir continuously. When the sugar has melted into an amber colored liquid, mix 6 tablespoons (90 g) of salted butter that's been cut into pieces into the pan. Allow the butter to heat until it melts into the sugar, which typically takes 2 to 3 minutes. Stir the mixture regularly to help the butter melt. When you add the butter to the sugar, the caramel mixture will bubble rapidly. Be careful to avoid burning yourself. You can use unsalted butter in the sauce if you prefer. No other changes need to be made to the recipe.
Question: What is a summary of what this article is about?
Heat the sugar in a saucepan. Stir the sugar constantly until it melts. Add the butter and stir until it melts.

Problem: Article: Studies have named the sun as the No. 1 cause of wrinkles. Wear a broad-spectrum (UVA and UVB) sunscreen with an SPF of at least 30. There is no need to go above SPF 50. You need to wear sunscreen even when it's not sunny. If you're tanned, this doesn't mean that you're protected from the sun. Wear sunscreen no matter what! Wearing sunscreen will not only prevent wrinkles; it will also reduce your risk of getting skin cancer. Reapply your sunscreen often at least every 2 hours. every day. Doctors recommend washing your face twice a day no more than that. Over-washing your face can strip your skin of its natural oils and moisture so that wrinkles appear deeper; it may even cause new wrinkles to form. Even if your skin is oily, don't wash your face more than twice a day, as it can irritate your skin and, if you have acne, it can cause further breakouts. People with mature skin (ages 40 and up) can likely get away with washing their faces with a cleanser each night, and only rinsing with cool water in the morning. Applying a toner to your skin after you've washed your face can help balance your skin's pH and keep it looking healthier. Just be sure to avoid toners containing alcohol, as this can dry out your skin. Many moisturizers contain ingredients aimed at fighting and preventing wrinkles. Apply a moisturizer to your face twice a day: once after your morning face-wash and once after your evening face-wash. There is little evidence to suggest that day and night creams are particularly different; however, some ingredients in moisturizers are made ineffective by the sun. For example, retinol, a highly effective wrinkle-fighter, is rendered inactive by sunlight, as are most prescription medications. The skin around your eyes is different from the rest of your facial skin: it is thinner and more delicate, quicker to wrinkle and droop. For this reason, it's worthwhile to use an eye cream in addition to your facial moisturizer. Look for an eye cream that contains collagen, vitamin C, peptides, and/or retinol.
Summary: Wear sunscreen. Wash your face Use a toner after you wash your face. Use a good-quality moisturizer that targets wrinkles. Use a good eye cream.

A topographer is a newer version of the keratometer. Your doctor will have you sit at a table and look into a bowl. This bowl's inner surface is covered in a pattern of concentric rings. A digital camera sits at the base of the bowl and charts the cornea's surface by measuring the reflected pattern in the eye. This basically creates a contour map of your eye, and it's an excellent technique for measuring irregular astigmatism. Most corneal topography tests measure 8,000 to 10,000 points on the cornea, making it the most accurate keratometry test. Other advanced ways of measuring astigmatism include autorefractors that measure refraction, and the IOLMaster that makes extensive measurements of the interior and exterior of the eye. The IOLMaster is usually used before cataract surgery. The Placido disc is an old-fashioned, hand-held device that is shaped like a giant lollipop. The disc has several sets of concentric circles painted on one side, and is used to measure the regularity of your cornea's surface. Your doctor holds the disc up to their own eye with the rings pointed towards you, and they look into your eye. Sit still and look straight ahead. The image of your cornea reflects back, and where there is irregular shape it makes the concentric rings look distorted to your doctor. This old-fashioned method can help to diagnose keratoconus, a disorder that causes irregular astigmatism due to thinning and protruding of the cornea. The shape of your posterior cornea (the back surface of the cornea) can influence the severity of your astigmatism. Keratometry can only measure the front of your cornea, but Scheimpflug imaging uses tomography to get more accurate readings of how thick your cornea is and what the back of it looks like. This method can be helpful in predicting how successful surgery may be in correcting your astigmatism.
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One-sentence summary --
Use a corneal topographer for more precise measurements. Try a Placido disc for irregular astigmatism. Use a Scheimpflug device to measure the posterior cornea.