Tadalista 20 mg (which contains tadalafil) can, in some cases, cause visual disturbances, although it’s not among the most common side effects. Visual disturbances are typically associated with other medications in the same class (PDE5 inhibitors, like sildenafil/Viagra and vardenafil/Levitra), but they can still occur with tadalafil. Visual Side Effects of Tadalista 20 mg  disturbances may include: Blurred vision Sensitivity to light (photophobia) A blue tint or color vision changes (known as cyanopsia) Vision impairment or trouble distinguishing between certain colors, especially in dim light These effects are generally temporary and tend to wear off as the drug leaves the system. However, in rare cases, more severe visual side effects can occur. Serious Visual Side Effects (Rare): Non-arteritic anterior ischemic optic neuropathy (NAION): This is a very rare but serious condition that can lead to sudden vision loss in one eye. While NAION is extremely uncommon, it's been noted in association with PDE5 inhibitors like tadalafil. If you experience sudden vision loss or notice changes in your vision while taking Tadalista, immediate medical attention is required. Sudden decrease or loss of vision: If you notice any significant changes in your vision or any sudden loss of vision, you should stop taking the medication and seek medical help immediately. Why These Visual Effects Occur: The mechanism behind these visual side effects is not fully understood but is thought to be related to how PDE5 inhibitors affect the cGMP (cyclic guanosine monophosphate) pathway, which plays a role in regulating blood flow in various parts of the body, including the eyes. PDE5 inhibitors can also affect the retina, which is why some users experience visual disturbances. What to Do If You Experience Visual Disturbances: If you experience mild visual disturbances, they usually resolve as the medication wears off. However, if the symptoms are persistent or cause significant discomfort, you should: Stop taking the medication and consult your healthcare provider. Seek immediate medical help if you experience more serious issues like sudden vision loss. If you're concerned about these potential side effects, or if you have any pre-existing eye conditions (like retinitis pigmentosa or any history of vision problems), it's a good idea to talk to your doctor before using Tadalista.