Final answer:
Ordinary glasses and sunglasses do not provide full coverage or adequate UV ray filtration for proper eye protection. Specialized protective eyewear such as eclipse glasses or welder's goggles are necessary for safe sun viewing and to prevent conditions like cataracts.
Step-by-step explanation:
Ordinary glasses and sunglasses are not sufficient protection because while some may block a percentage of UV radiation and offer some degree of protection, they may not offer full coverage needed to protect eyes from sunlight coming in from all directions. Specialized protective eyewear is designed to give full coverage and protect against both UVA and UVB rays, which can cause serious eye conditions such as cataracts.
Additionally, sunglasses, such as photochromic lenses, while offering convenience by darkening in sunlight, are not adequate for looking directly at the sun or for protecting the eyes from extreme exposure that could result in severe damage or the suppression of the immune system.
Safe viewing of the sun, such as during an eclipse or similar events, requires specially designed eclipse glasses or welder's goggles that have been made to filter out harmful rays. Ordinary sunglasses are definitely not safe for this purpose, and eye safety must always be considered when exposed to potential UV damage.