Vision changes such as increased sensitivity to light, blurred vision, or trouble telling blue and green colors apart may also occur. Other Uses This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Rarely, a sudden decrease or loss of hearing, sometimes with ringing in the ears and dizziness, may occur. Canada residents can call a provincial poison control center. In Canada – Call your doctor for medical advice about side effects. In the rare event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and get medical help right away, or permanent problems could occur. Getting a prescription for Viagra online You can also get a prescription for Viagra online through a telehealth platform like Felix.You cannot legally import a prescription drug unless you are a practitioner, a drug manufacturer, a wholesale druggist, a registered pharmacist, or a resident of a foreign . AdSave on Health Products. Free 2-Day Shipping with Amazon Prime.1M+ visitors in the past month. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana .