“Long-sightedness [presbyopia] caused by age could be due to proteins in the lens of the eye that are converted from a fluid solution to a solid, glassy state. This has been shown in a study by researchers from institutions including Lund University,” according to a Medical News Today post. “Around the age of 40-50, many people find their sight deteriorates and they need to use reading glasses. This age-related long-sightedness is thought to be due to a reduction in the elasticity of the lens in the eye. A new research study appears to have put its finger on the details of what happens in the eye when long-sightedness develops.” Read more.