Q: What exactly is astigmatism?
A: Astigmatism is usually caused by an irregularly shaped cornea, the front surface of the eye. Instead of being a perfect sphere, like a ball bearing or a marble, it can become a little more like a football, being more curved in one direction than the other. This brings light into focus at more than one point on the retina at the back of the eye, resulting in blurry or distorted vision.
Q: Does reading my smartphone or tablet in the dark damage my eyes?
A: Reading from a tablet or smartphone in the dark is okay for your eyes, as long as it's not for a long period of time. These devices have decent lighting and good contrast. However, they give off blue light, and long-term exposure may cause damage to the structures of the eye. As well, studies have shown that blue light at night disrupts melatonin production and interferes with healthy sleep cycles. Optometrists recommend wearing blue light blocking eyewear for extended digital device use, and limiting screen time during the last hour before bedtime.
Q: What are cataracts and how do they affect my vision?
A: A cataract is a gradual clouding of the crystalline lens, located inside the eye, causing decreased vision. Cataracts most commonly occur with aging, and are a normal part of the aging process. Other causes of cataract development include ocular trauma/surgery, radiation, smoking, systemic disease (metabolic and genetic conditions), and certain medications (particularly corticosteroids). Symptoms of cataract vision loss depend on the type, location, and severity of the cataract. Cataracts may cause gradual blurry vision, halos around lights, poor night vision, prescription changes, and glare symptoms. A cataract is treated with outpatient surgery, in which the crystalline lens is removed and replaced with a clear lens implant. Surgery is typically done with local anesthesia, with minimal or no complications. Nearly all patients achieve improved vision and often do not require glasses post surgery. Cataract surgery is one of the safest and most common surgeries performed in the United States. Your optometrist will evaluate your eyes for cataracts at each comprehensive eye exam. Please let your optometrist know if you experience any of the above symptoms.