Lens elements upset

While the outer lens surfaces will be clean, the inner components may be affected or even damaged.
Microscope objectives are complex constructions.
It is too risky.

I hope there is no mild on the lens, because that is irreparable. When you look in the lens barrel, and you see an element with a tray haze over its surface, there is a chance it has mould on the element. Making the lens unusable.

follow this steps and fix it. God bless you
Clean a DVD disc:

1. Hold the disc by its central hub and outside edge.
2. Blow dust from the bottom surface with a can of compressed air.
3. Clean dirt and fingerprints from the bottom surface with a lint-free cloth dampened with CD/DVD-cleaning fluid or denatured alcohol, wiping from the center outward.

Remove screws from the rear of the case to remove the top and access internal components.
Service a DVD player disc tray:

1. Open the housing by removing mounting screws and anything blocking the tray. Press the open/close control to the extend tray, then unplug the unit. To remove a clip-on tray front, brace the tray and slide the panel to one side.
2. Unplug cables between the front panel and the interior. Remove any screws securing the front panel and remove the panel. If it won't move, check beneath it for clips or additional screws.
3. Remove the hold-down on top of the disc tray and gently pull the tray out of the player. Clean the travel rail and guides with a swab dampened with denatured alcohol. Lubricate lightly with white lithium grease.
4. Remove the drive belt (using gloves or tweezers) to inspect for dirt, water, or damage. Clean with a lint-free cloth moistened with denatured alcohol. If the belt is damaged, replace it.

Once inside a DVD player, you'll see that it's mostly made up of circuit boards. Not much to work on-except testing a fuse and maybe replacing the tray motor.
Service a DVD tray motor:

1. Unplug the player and test the motor with multimeter
   
2. Unplug the motor plug and spray it with electrical contact cleaner, then plug it back in.
3. To remove the motor, unscrew or depress the end of each bale and lift out the motor. Replace the motor if necessary.

Clean the objective lens:

1. Remove the housing and lift the hold-down clamp to expose the lens.
2. Remove dust with canned air or soft brush. If needed, use a foam swab or a camera-lens tissue dampened with lens fluid.

follow this steps and fix it. God bless you
Clean a DVD disc:

1. Hold the disc by its central hub and outside edge.
2. Blow dust from the bottom surface with a can of compressed air.
3. Clean dirt and fingerprints from the bottom surface with a lint-free cloth dampened with CD/DVD-cleaning fluid or denatured alcohol, wiping from the center outward.

Service a DVD player disc tray:

1. Open the housing by removing mounting screws and anything blocking the tray. Press the open/close control to the extend tray, then unplug the unit. To remove a clip-on tray front, brace the tray and slide the panel to one side.
2. Unplug cables between the front panel and the interior. Remove any screws securing the front panel and remove the panel. If it won't move, check beneath it for clips or additional screws.
3. Remove the hold-down on top of the disc tray and gently pull the tray out of the player. Clean the travel rail and guides with a swab dampened with denatured alcohol. Lubricate lightly with white lithium grease.

Remove the drive belt (using gloves or tweezers) to inspect for dirt, water, or damage. Clean with a lint-free cloth moistened with denatured alcohol. If the belt is damaged, replace it. Service a DVD tray motor:

1. Unplug the player and test the motor with multimeter
2. Unplug the motor plug and spray it with electrical contact cleaner, then plug it back in.
3. To remove the motor, unscrew or depress the end of each bale and lift out the motor. Replace the motor if necessary.

Clean the objective lens:

1. Remove the housing and lift the hold-down clamp to expose the lens.

Remove dust with canned air or soft brush. If needed, use a foam swab or a camera-lens tissue dampened with lens fluid.

Okay. I just wanted to scare you away from ruining a perfectly good (or nearly so) lens, but a learning project is a different matter. And a lens collimator is not that hard to build. One source is the book "Camera Maintenance & Repair" by Thomas Tomosy. I'm sure a quick Google search would show even more.

I did the same thing myself decades ago, taking apart a damaged zoom lens. Unfortunately, I never got it working properly again :-( But it was an educational experience, even though I didn't have a lens collimator...

This is actually a very common situation for older lenses. You should take the lens to a trained technician and have them clean the inner elements of the lens. Often times they can, if the fungus isn't too bad. In extreme situations, they will need to replace the element itself.

The fading (flare) you see could simply be a finger smudge or other stuff. One little scratch won't do it, you'd have to take sandpaper to the lens to see obvious flare.

It's actually harder to scratch a modern lens than most people think. When it happens, it's usually during cleaning when a tiny piece of grit is on the surface and gets rubbed in by the cleaning cloth/lens tissue.

So the first step in cleaning a lens surface is to be sure you remove all dust and dirt without rubbing. The lens cleaning kit you can find in any camera store is a start -- it contains a blower brush. With the lens surface to be cleaned facing down (so dust falls away), brush gently with the tips of the bristles to dislodge stuff. Then use the blower to blow it away. Repeat as needed.

If you still see dust and dirt which seems to be stuck on the surface, take a piece of the lens tissue from the kit and put several drops of the cleaning solution on it, enough to get it pretty damp. (Always apply cleaning solution to the tissue or cloth, never drop directly on the lens surface.) Cover the lens surface with the damp tissue, pressing it into the corners, but do not slide the tissue across the surface. Just lift it away. Repeat with another section of tissue.

Then take a full sheet, wad it lightly, and wet it. You are going to rub lightly, using a roll-up motion as you move the tissue so that dust/dirt is lifted away from the surface and fresh tissue is always coming in contact with the surface. Repeat as needed until there isn't any visible stuff.

Final cleaning can be done with a fresh piece of tissue and a bit of mist from your breath. Mist the surface, and lightly polish with the tissue to remove any remaining cleaner residue.

Its more like a distorted inner zoom barrel or sand and dirt inside  the inner barrel will need to be replaced or you need to dismantle and clean out